Dicaelus (Paradicaelus) furvus Dejean 1826

Dicaelus furvus x carinatus
Dicaelus furvus Blatchley (not Dejean), 1910: 115.
Dicaelus ovalis Blatchley (not Le Conte), ibid., p. 116. — Brimley, 1938: 122.
Typical members of this subspecies exhibit the following combination of characters: Males, length 15.4 mm. or less, ratio width elytral interval 5/W El int. 4, 1.13 or less; females, length 15.1 mm. or less, W El int. 5/W El int. 4, 1.18 or less; pronotum and dorsal surface of head rugulose, the lines of macrosculpture relatively fine and relatively far apart, integument almost smooth, shining. Specimens of this species from Pennsylvania and localities south and east of the Appalachians at least as far south as northern Virginia and Washington, D. C. may be included in the typical subspecies.
Variation. — A summary of data on variation in total length is presented in table 24 and of values for the ratio W El int. 5/W El int. 4 in table 25 (E. Pa., D.C.-Md. and W. Pa. samples). Lateral margins of the pronotum vary slightly in roundness and the anterior margin varies slightly in width. Variation in extent of lateral beading of the pronotum for a composite sample of eight specimens of both subspecies and intermediates is as follows : complete — 2 specimens ; about 3/4 length of lateral margin — 14; about 1/2 — 52; about 1/4 — 1; beading completely absent — 8. Width in a composite sample of D. f. furvus varies as follows: 20 males, 5.8-7.0 mm. (6.3 mm.) ; 20 females, 5.97.1 mm. (6.6 mm.). Number of setae near the apical margin of the 6th abdominal sternite varies as follows: 20 males, 2-5 (3.4) ; 20 females 6-10 (7.4). Synonymical Notes. — The type series of Dicaelus ovalis Le Conte consists of five specimens. The type specimen, a female collected in the southern states, is slightly less than 22.0 mm. in length, has a value of 1.17 for the ratio W El int. 5/W El int. 4, and the dorsal surface of the head and pronotum is rugose. The remaining specimens were collected in the " middle states ", and have the dorsal surface of the head and pronotum rugulose ; the ratio W El int. 5/W El int. 4 has the following values : " ovalis 2 "■ — 1.31 ; " ovalis 3 " — 1.12 ; " ovalis 4 " — 0.96; " ovalis 5 " — 1.12. " ovalis 2, 3, and 4 " are females, " ovalis 5 " is a male. I neglected to obtain the lengths of these specimens.
I do not believe that the specimen described by Le Conte is the one now labelled as type. The original description calls for a female 0.62 in. in length (15.5 mm.), with head rugose, and pronotum transversely lightly rugose. Subsequently Le Conte gave additional characteristics of ovalis by stating that: " its form is a little broader, the interstices of the elytra are all equal, and the 8th [7th?] is more acutely elevated, (1853 : 388). The combination of the elytral interval character (interstices) with the diagnostic features given in the original description would seem to indicate that Le Conte's concept of ovalis was not based on the specimen which at present bears the type label. Therefore, one of the other specimens in the series is really the type, although the elytral intervals in none of them are all of the same width. If this is true, then the type locality of ovalis must be in the " middle states ". As the type locality of D. furvits as restricted by me is eastern Pennsylvania, and as Pennsylvania is included in Le Conte's definition of the " middle states ", then it follows, or at least seems reasonable if what was said above is true, that ovalis is a synonym of jurvus Dejean.
Type locality. — The exact type locality of Dicaelus f. jurvus is not and cannot be known with certainty. However, Lindroth (in litt.) has informed me that the type is very much like a specimen from eastern Pennsylvania. As the type of jurvus was sent to Dejean by Say, and as Say lived for a time in eastern Pennsylvania and could have collected the specimen there, I have restricted the type locality to that state, east of the Susquehanna River.
Distribution. — This subspecies ranges from Pennsylvania southward on the piedmont and coastal plain, at least to the latitude of Washington, D. C. Specimens from North Carolina, Tennessee, Ohio, In
diana, and Illinois are regarded as intergrades between D. j. jurvus and D. j. carinatus.
Notman (in Leonard, 1926:219) records Dicaelus ovalis from Buffalo, and from McLean Bogs (Tompkins Co.), New York. I have not been able to verify these records.
I have seen twenty-seven males and thirty-eight females collected in the following localities.
District of Columbia: Washington; Woodridge. Maryland: Harford County; Edgewood. Washington County; Hagerstown. Pennsylvania: " Pa." Allegheny County ; Allegheny, Pittsburgh. Centre County ; State College, Shingleton. Cumberland County ; Camphill, Enola, Le Mogne, Cumberland. Dauphin County ; Rockville. Delaware County ; Castle Rock. Lancaster County ; Lancaster. Lehigh County ; Allentown. Northampton County ; Easton, Wind Gap. Philadelphia County; Lawndale, Philadelphia. County not determined, Heckton Mills. Virginia : Amherst County ; Sweet Briar. County not determined ; Difficult Run. West Virginia : " W. Va."
Fourteen males and twenty females collected in the following localities are regarded as intergrades between j. jurvus and /. carinatus.
Illinois : " 111." " Champaign County ; Urbana. " Lawrence County." Indiana : " Ind." " Crawford County." " Dearborn County." " Gibson County." " Koscuisko County." " Posey County." " Putnam County." " Vigo County." North Carolina : " N.C." Buncombe County ; Asheville. Tennessee : Cumberland County; Grassy Cove. Fentress County; Allardt. Hamilton County; Chattanooga. Obion County; Obion. Wilson County; Cedars of Lebanon St. Pk. Ohio: "Ohio."

Dicaelus (Paradicaelus) furvus Dejean
This species is likely to be confused only with specimens of Dicaelus elongatus that have fewer than three setigerous punctures on each side of the pronotum. (See distinguishing features of elongatus for detail). In elongatus the discal intervals of the elytra are all of about the same width, but in j. carinatus 3 and 5 are usually wider than the remaining discal intervals.
Restricted to the United States east of the Rocky Mountains and probably west of the 100th Meridian, Dicaelus jurvus ranges on the
coastal plain and piedmont of the east coast from at least central Pennsylvania and New Jersey southward to northern Florida; westward on the Gulf Coast at least to Louisiana (probably also eastern Texas), and north in the Mississippi Valley to eastern Kansas and Nebraska ; thence eastward through Illinois, Indiana, and Ohio.
The diagnosis presented in the key covers three named forms : jurvus Dejean, carinatus Dejean, and ovalis Le Conte. These have been characterized by their authors, or other students of the genus Dicaelus, as follows : jurvus — size smaller, carina formed by interval 7 of the elytra lower, and elytral intervals on the disc only moderately alternating in width (3 and 5 slightly but distinctly wider than 1, 2, 4, and 6) ; carinatus — size larger, carina formed by interval 7 more strongly developed, and elytral intervals 3 and 5 considerably wider than 1, 2, 4, and 6; ovalis — size smaller, pronotum more broadly rounded laterally, elytral carina as in carinatus, and intervals 3 and 5 as wide as 1, 2, 4, and 6, but not wider. An additional character, mentioned only by Le Conte in the original description of ovalis, is the rugosity of the head and pronotum. Specimens referable to carinatus on the basis of the above characterization have the dorsal surface of the head and pronotum strongly rugose, while specimens referable to jurvus and ovalis have these same areas varying from smoother and more shining than in carinatus to almost completely smooth.
As the supposedly diagnostic characters of the forms mentioned above are only portions of a morphological continuum, I regard these three as representatives of the same species and not as distinct species. The apparent relative height of the elytral carina seems to be a direct correlative of size, i.e. larger specimens have the carina apparently, but not really, more strongly developed simply because of the general increased body size. The pronotal character given for ovalis seems to be individually variable, whereas the remaining characters seem to vary geographically.
Geographical Variation. — All of the specimens available were arranged in a series of nine samples, as follows : " E. Pa.", Pennsylvania, from the environs of the Susquehanna River Valley and eastward ; " Md.-Va." Maryland, District of Columbia, West Virginia, and Virginia : " W. Pa.", Allegheny County, Pennsylvania; " O.-IIL", Ohio, Indiana, Illinois; " Mo. -Ark.", eastern Kansas, Missouri, and Arkansas; " la.", Iowa; " Tenn.", Chattanooga, and westward in Tennessee; " N. C", North Carolina; " Ala.-Miss.", Alabama and Mississippi, piedmont and coastal plain.
Relative rugosity of the dorsal surface of the head and pronotum is, in general, less pronounced in specimens from the north and east, distinctly coarser and more distinct in specimens from the north and west, and most pronounced in specimens from Alabama and Mississippi. Lustre of the integument is correlated with rugosity : the coarser the rugosity, the more opaque the integument.
Size is expressed here in terms of total length (table 24). The more northern samples are composed of individuals which on the average are smaller than are the components of the more southern samples. Failure to form a neat cline, i.e. with the geographically most widely separated samples also morphologically most widely separated, may be due, at least in part, to sampling error which is probably large.
To express the character involving degree of alternation of width of the elytral intervals numerically, the width of interval 5 and interval 4 was measured for each specimen at a point on the left elytron slightly below the apex of the scutellum. Then the width of interval 5 was divided by the value obtained for the width of interval 4 to yield a single numerical value. These data are summarized in table 25. The most salient feature emerging from a statistical analysis of these data was that the differences between the E. Pa. and Ala.-Miss. samples were statistically significant, and that these samples could be regarded as being subspecifically distinct. (For details see Ball, 1954: tables 3134). Assuming the E. Pa. and Ala.-Miss. samples represented approximately topotypical populations of furvus and carinatus, these samples were used for arriving at a hybrid index by utilizing the following method. Typical specimens of furvus received a value of 2, typical specimens of carinatus a value of 6. " Typical " was defined in this way: a specimen falling within 1 + S. D. of the mean of the E. Pa. sample for one character was regarded as " typical " for that character and assigned a value of 1. If a specimen fell within 1 + S. D. of the mean for both characters, this individual received a value of 1 for each character, and the sum of these yielded the hybrid index value of 2. On the other hand, a specimen falling within 1" S. D. of the mean of the Ala.-Miss. sample received a value of 3 for each character within this
range, and a hybrid index value of 6. Specimens intermediate for one or both characters received intermediate values. The basis for determining the hybrid index values is presented in table 26.

Dicaelus furvus is a species of ground beetle in the family Carabidae. It is found in North America.