54 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



able. It measures 0.11 to 0.155 mm in length, and about 15/i at the 

 widest point near the anterior end. The genital cone is 0.13 to 0.145 

 mm long and 0.09 to 0.11 mm wide at the base. The bursa is obliquely 

 truncated; its rays are of the usual pattern. The common trunk 

 of the dorsal ray usually bifurcates near its middle, and each branch 

 almost immediately divides again. The inner rays are again divided 

 for from one-half to one-third their length. 



Female: The total length varies from 10 to 13.75 mm; width from 

 0.2G to 0.33 mm. The mouth capsule is 0.16 to 0.18 mm long and at 

 the base about as broad as long. The esophagus is 0.35 to 0.47 mm 

 long. The nerve ring and excretory pore are 0.28 to 0.32 and 0.4 to 

 0.51 mm, respectively, from the anterior end. The vulva is 7 to 

 9.13 mm from the anterior end and therefore in the posterior part 

 of the body. The vulva divides the body in the ratio of 1.6:2; the 

 lips of the vulva are very prominent, measuring about 0.11 mm in 

 length. The uteri are divergent, and therefore this species falls into 

 Ortlepp's group A. The rest of the female genital system is quite 

 typical for the genus. The eggs measure 67/a to 75ft by 38/t to 46/i. 

 The tail varies in length from 0.3 to 0.4 mm, and it ends bluntly. 



Hosts. — Agkistrodon mok<isen^ Heterodon contortrix^ Pituofkh 

 sayi^ Natrix rhoinbifera., N. sipedon fasclata^ Lampropeltis getidus 

 holhrooki, Thmnnophis proxhniis^ and Mieimrus fulvius. 



Habitat. — Stomach. 



Locality. — Houston, Tex. 



Type specwiens. — U.S.N.M. Helm. Coll. No. 31704; paratype, No. 

 31705. 



Retiiarhs. — This parasite closely resembles KalicephaJus coronellae., 

 which Ortlepp found in the stomach of a North American snake 

 {Coro-nella tnangulmn) dying in the Zoological Gardens of London. 

 K. agkistrodontis is a much smaller form ; the buccal capsule is more 

 elongate; the female tail is much shorter (in actual measurement, 

 but about the same proportionately) ; the spicules and gubernaculum 

 are both shorter, in actual measurements, and the gubernaculum is 

 shaped differentl3\ 



KALICEPHALUS AGKISTRODONTIS FLAGELLUS, new subspecies 



Subspecific diagnosis. — These worms differ from the typical variety 

 in the following respects : They are smaller, the males vary in length 

 from 6.3 to 7 mm, the females from 6.72 to 8.15 mm. The female 

 tail is shorter measuring 0.24 to 0.32 mm in length. The inner rays 

 of the dorsal ray are divided for less than one-fifth their length, and 

 in one specimen there is no bifurcation at all. 



Hosts. — Coluber -flagellwm and C. constrictor flaviventris. 



Habitat. — Stomach. 



Locality. — Houston, Tex. 



