322 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ii4 



It is likewise a matter of interest that the species occurs in an area 

 both geographically and ecologically remote from the main center of 

 speciation in eastern United States. 



Camburincola virginica, new species 



Figures 35, 3G 



Type specimens. — Holotype and parat3^pe, USNM 29942, from 

 Camharus acuminatum collected in a small slow stream 4.7 miles north 

 of Petersbm-g, Chesterfield Count}', Vkginia, by P. C. Holt and 

 M. L. Bobb, :May 31, 1949. 



Diagnosis.- — With the characters of the group, easily recognized 

 within the genus by the combination of a specialized prostate with 

 small terminal bulb and a large lateral deferent lobe near the middle 

 of the spermiducal gland. The spermatheca is ver}- long and slender, 

 extending to the middorsal region. 



Description. — A moderately small worm, up to 2.0 mm. in maxi- 

 mum length, the body profile very slightly fusiform with the greatest 

 diameter at segment vii, gradually tapering toward each end; proso- 

 mites only slightly longer than metasomites and of about the same 

 diameter. Caudal sucker wider than segment i and head. 



Head rather small and short, only slightly longer than broad, of the 

 same diameter as segment i, peristomium set off by a basal groove and 

 somewhat flared, but essentially with entire margins. Jaws small, 

 anisomorphic but equal in size, dental formula 5-4, teeth virtually 

 subequal in size and shape, the median dorsal or paramedian ventral 

 teeth slightly the largest. 



Male reproductive system large, filling one side of the segment 

 lateral to the gut. Bursa elongate fusiform, 1.5 to 2 times as long as 

 broad, about equally divided into atrium and penial sheath, merging 

 abruptly into the slender ejaculator}' duct. The latter a little more 

 than half as long as bursa, and slightly enlarged at its midlength. 

 Spermiducal gland large, du'ected obliquely cephaloventrad across 

 the segment, extendmg down to the level of midlength of the bursa, 

 thence merging into the anterior deferent lobe which proceeds mesad 

 into the segment. Posterior deferent lobe large and distinct, from 

 the midlength of the gland, directed caudad and concealing most of 

 the ejaculatory duct, beyond which it is bent abruptly ventromesad, 

 merging mto the posterior deferent duct. Prostate gland about two- 

 thirds the maximum diameter of the spermiducal gland, but less than 

 half its length, composed of large vacuolated cuboidal cells very dif- 

 ferent from the cells of the spermiducal gland; termmating in a small 

 and inconspicuous clear space doubtless homologous with the large 

 bulb of the Philadelphica group. 



