22 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.81 



usually overlap the intestinal ceca to some extent. The posterior 

 groups begin a little cephalic to the ovary and extend to the testes. 

 They are fairly compact and usually lie outside the intestinal ceca. 



Hosts. — Natrix sipedon and N. si-pedon fasciata. 



Habitat. — Mouth. 



Locality. — Philadelphia, Pa., and Houston, Tex. 



Specimens.— [J.^.'^M. Helm. Coll. Nos. 30885 and 30886. 



Remarks. — This form is apparently very similar to Renifer natri- 

 cis MacCallum, from the mouth of Natrix taxispilota. The descrip- 

 tion of this species is in many ways misleading. The name is not 

 stated to be new, and in the first paragraph of the description 

 MacCallum seems to confuse this worm with certain species of trema- 

 todes that are known only from birds and are usually referred to 

 the genus Prosthogonimus. MacCallum states that Renifer natHois 

 possesses a seminal reservoir, but as this is not known in any other 

 species of Renifer it seems doubtful. Differences that seem to justify 

 the separation of MacCallum's form from Leidy's are the distribu- 

 tion of the anterior groups of vitellaria, the presence of a pre- 

 pharynx, a relatively larger acetabulum, and the position of the 

 genital pore on the opposite side of the body. 



Genus LECHRIORCHIS Staflford, 1905 



Sum wait (1926) has reviewed the status of this genus, and she 

 has carefully pointed out the discrepancies and possible errors of 

 past authors. Because of differences in the intestinal ceca and in 

 the location of the genital pore, she has suggested that the genus 

 be divided. 



LECHRIORCHIS VALIDUS Nicoll, 1911 



Several specimens that I have collected from the lungs and mouths 

 of the hog-nosed snake \Heterodon contortrix {=H. plafyrhinus)'] 

 and the king snake {Lampropeltis getvlus holbrooki) are referred 

 to the above species. These specimens differ in some particulars 

 from Nicoll's description of the types, but in my opinion the differ- 

 ences admit of other explanations than the erection of a new species. 

 Nicoll states that the esophagus is three-fourths the length of the 

 pharynx, while in my material the esophagus, though variable in 

 length, is always longer than the pharynx. In one of Nicoll's figures 

 of L. validiis, however, the esophagus is distinctly the longer. In 

 all other particulars my specimens agree exactly with Nicoll's de- 

 scription, and therefore I refer them to his species. Manter (1927) 

 has reported this species from the body cavity of the blue racer 

 {Coluber constrictor flaviventris) . 



