348 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lu 



1958, Holt, (PCn 846); large stream 5.1 miles east of Compton on Ky. Hy. 15, 

 July 31, 1958, Holt (PCH 847). 



North Carolina: macon county: Spillway of Lake Ravenel, Highlands, 

 July 8-15, 1958, Hoffman (PCH 875) ; Buck Creek drainage 3.5 miles northwest 

 of Highlands, August 3, 1958, Hoffman (PCH 884). 



Tennksseb: Cumberland county: White Creek, 0.25 mile northwest of 

 Alloway, May 3, 1959, Holt and Ford (PCH 903). 



Cambarincola chirocephala Ellis 



Figures 43-50, 57 



Cambarincola chirocephala Ellis, 1919, Proc. U.S. Nat. Mus., vol. 55, p. 263, 

 figs. 18, 19.— Goodnight, 1940, Illinois Biol. Monogr., vol. 17, no. 3, p. 37 

 (in part. 111., Ind., Ky., Mo., ?Ala. records); 1910, Rep. Reelfoot Lake Biol. 

 Station, vol. 4, p. 171 (?Tenn. record). — Holt and Hoffman, 1959, Journ. 

 Tennessee Acad. Sci. vol. 34, p. 103. 



Type specimen. — Holotype, USNM 17713, from Orconectes virilis 

 collected at RoUa, Phelps County, Missoui'i, by J. Barley. This 

 specimen is mounted flattened dorsoventrally, showing the jaws 

 clearly; the reproductive sj^stems are obscured. 



Diagnosis. — A small member of the Philadelphica group, recog- 

 nized by the distinctly disparate anisomorphic jaws; by the reduced 

 size of the spermiducal gland and prostate (both often shorter than 

 the bursa); and by the elongate, slender, gradually enlarged sper- 

 matheca. 



Description. — ^Bocly small, ranging from 1.5 to 2.5 mm. in length, 

 the greatest diameter at segment vii; prosomites of all segments 

 larger than metasomites. Diameter of segment i less than that of 

 head; segments ix and x reduced, the caudal sucker abruptly enlarged, 

 equaling or sm'passing diameter of head. 



Head of normal size and form for the genus, larger than segment i, 

 as long as the first three body segments combined. Peristomium 

 conspicuously set off by a basal constriction, flared, its margin pro- 

 vided with four small lobes on the dorsal side and two broad, lower 

 lobes on the ventral. 



Jaws disparate in both dorsal and lateral aspects, anisomorphic; 

 broadly triangular. Dorsal jaw largest, 1.5 to 2 times as broad as 

 tlie ventral, tlie median tooth very conspicuous, lateral cusps small 

 or obscure. Ventral jaw subtrapezoid, with two small paramedian 

 apical teeth and a median sinus, and a smaller sublatcral cusp on 

 each side halfway to the base. 



Male reproductive system moderate in size, extending dorsal 

 through about tliree-foiu-ths of segment vi. Bursa elongate, pyriform, 

 2 or 3 times as long as its greatest diameter, the latter more tlian 

 half the length of the ventral part of the segment. Atrial portion 

 of bursa somewhat longer than the penial sheath. Ejaculatory 

 duct long and slender, two-thirds to three-fourths as long as the 



