ART. 17 PARASITES OF AMPHIBIA AND EEPTILIA HARWOOD 21 



RENIFER ANIARUM (Leidy. 1890) 



Plate 2, Figure 3 



Leidy (1890) described this parasite under the name of Distomum 

 aniaruTii, but since that time the form seems to have been ignored 

 by helminthologists. Leidy's description, while in many points very 

 inadequate from the standpoint of modern taxonomy, is, neverthe- 

 less, sufficiently detailed to leave little doubt as to the specific iden- 

 tity of his parasites and of my material from the same host. Since 

 Leidy's description is so brief, the species is redescribed as follows: 



Speci-fic diagnosis. — Renifer: Small worms with their sides par- 

 allel, rounded at both ends or pointed at the posterior end, length 

 2.25 to 3.5 mm, width 0.7 to 1.1 mm. The cuticula is well armed 

 with spines in the anterior regions, but posteriorly the spines are 

 weak and scattered. The oral sucker is subterminal and circular in 

 outline, and the mouth opening points cephalo-ventrad. The diam- 

 eter varies from 0.3 to 0.42 mm. The acetabulum lies close to the 

 center of the body and has a diameter of 0.46 to 0.66 mm. It is, 

 therefore, about one and one-half times the diameter of the oral 

 sucker. A short prepharynx is followed by a globular or oval 

 pharynx 0.13 to 0,16 mm in diameter. The length of the esophagus 

 equals about twice the diameter of the pharynx. The intestinal di- 

 verticulae reach to the testes. The testes are oval or circular in 

 outline, and the margins may be slightly irregular. They are usually 

 symmetrically placed, but they may be oblique. They measure from 

 0.16 by 0.2 mm to 0.38 by 0.36 mm. The vasa efferentia may either 

 join as they enter the cirrus sac or enter separately. The cirrus sac, 

 which contains the seminal vesicle and pars prostatica, extends from 

 a point, slightly to the left of the median line and posterior to the 

 intestinal fork, diagonally across the body to the genital pore, which 

 lies on the right side at the level of the oral sucker. The ovary is a 

 globular structure, which lies on the left side, posterior to the acetab- 

 ulum but anterior to the testes. Its diameter varies from 0.145 to 

 0.18 mm. The ootype and Mehlis's gland lie median and usually 

 slightly caudal to the ovary. A short oviduct may or may not be 

 discernible in whole mounts. A small yolk reservoir is present, but 

 the spermatozoa are stored in the ovarian end of the uterus. The 

 uterus, with many loops and coils, descends between the testes, nearly 

 to the caudal end, returns by the same course to the caudal end of 

 the cirrus sac, where the loops cease, and runs parallel and caudal 

 to the cirrus sac to the general pore. The eggs vary from 32;u, by 

 20/i to 42/i by 25^. The vitellaria are divided into two groups by 

 the acetabulum. The anterior groups extend from the pharynx to 

 points a little caudal of the cephalic margin of the acetabulum. They 



