356 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



ture — isomorphic and bipentadont in the Tennessee worms, aniso- 

 morphic and pentatetradont in meyeri. Two hkelihoods can be 

 considered: 1, The original types of meyeri may have been compos- 

 ite. Goodnight's account of the jaws was based on the paratype. 

 Unfortunately, the dentition cannot be made out with certainty in 

 the holotype, owing to its orientation on the slide; 2, the types of 

 meyeri may be aberrant specimens with respect to jaw structure, if 

 we assume that both are anisomorphic. 



The question is one which can be settled only by the study of a 

 series of fresh specimens from the type locality. On the basis of 

 present knowledge of the gToup, it seems utterly unlikely that virtual 

 identity in form of the sex organs would be contra verted by a basic 

 difference in jaw structure. 



For the present, however, I refrain from identifying the Tennessee 

 worms as meyeri, remarking only their great similarity to the type of 

 that species, and commending the matter to someone having the 

 opportunity to seciu"e topotypes of the species. 



Cambarincola fallax, new species 



FiGUEES 58-60, 62, 63 



Cambarincola philadelphica (in part) Ellis, 1919, Proc. U.S. Nat. Mus., vol. 55, 

 p. 262.— Goodnight, 1940, Illinois Biol. Monogr., vol. 17, no. 3, p. 38.— Holt, 

 1949, Journ. Morphology, vol. 84, p. 535 et seq. 



ICamharincola okadai Yamaguchi, 1933, Proc. Imp. Acad., vol. 9, no. 4, p. 191; 

 1934, Journ. Fac. Sci. Hokkaido Imp. Univ., vol. 3, no. 3, p. 190. 



Type specimens. — Holotype and four paratypes, USNM 29945, 

 from Camharus longulus subsp. collected in Maiden Spring Creek, 

 about 1 mile east of Wardell, Tazewell Comity, Virginia, on June 19, 

 1959, by R. L. Hoffman. Additional paratypes from the same 

 collection, PCH 904. 



Diagnosis. — A moderate to large species of the Philadelphica group 

 characterized by the combmation of homognathous, pentadont jaws 

 and conspicuous elongate peristomial tentacles. 



Description. — A moderate to fairly large species, up to about 

 4.0 mm. in length. Body form rather slender, without distinct 

 enlargement in diameter in going caudad to the middle of the length. 

 Prosomites about twice as long as metasomites and very distinctly 

 larger in diameter, imparting a pronounced annulate body profile. 

 SegTnents ii to vii usually of about equal diameter. 



Head moderate in size, about as long as first thi'ee body segments 

 combined, its diameter about equal to that of segment ii, equal to 

 or slightly larger than diameter of caudal sucker. Peristomium 

 large, set off by a deep basal constriction, almost half the total head 

 length; the dorsal half often a little flared, with four distinct blunt 



