259] PROTEOCEPHALIDAE—LA RUE 259 



there remain two characters which are deemed of sufficient value to 

 warrant a separation of the snake Proteocephalids into two genera. 

 These characters are the structure of the suckers and the length of the 

 neck. The first character has already been discussed. All the known 

 species of Ophiotaenia have relatively long necks, i. e., 2-8 mm. long 

 while C. gerrardii has a short neck. Monticelli was amply justified in 

 separating this species from his genus Tetracotylus, sensu latu. How- 

 ever since it has been shown that his type species of Tetracotylus should 

 be separated from the genus Proteocephalus and even from the family 

 Proteocephalidae, his arguments in justification of his action are not 

 repeated. 



Monticelli 's (1899) diagnosis of the genus Crepidobothrium reads: 



"Capo inerme, grande, rigonfio, piramidato : ventose ellittiche, posteriormente 

 a margine interrotto e rientrante nel cavo della ventosa. Aperture genitali margi- 

 nali, irregolarmente alternanti. Orifizio dell'antro genitale subventrale, largo : 

 sbocco della vagina dorsalmente e disotto alia tasca del pene : ovario piccolo : 

 testicoli piccolissimi, numerosi, collocati nel mezzo della proglottide, internamente 

 alia musculatura longitudinale interna, in unica serie. Utero allungato, tubolare, 

 sacciforme. Vitellogeni piccoli, numerosi, periferici. Uova ravvolte in una capsula 

 gelatinosa." 



His diagnosis does not require much amplification but may be re- 

 stated thus. Crepidobothrium Monticelli : Head large, swollen, pyra- 

 midal, tetragonal, unarmed. Fifth sucker vestigial. Suckers inversely 

 cordate, posterior margin interrupted and re-entrant into sucker cavity. 

 Genital aperture marginal, irregularly alternating. Vaginal opening 

 dorsal to cirrus-pouch. Vagina anterior or posterior to cirrus-pouch. 

 Testes in two lateral fields anterior to the ovary. Ovary bilobed, lobes 

 irregular, relatively small. Uterus tubular, median, possessing in ripe 

 proglottids numerous lateral outpocketings. All genital organs within 

 inner longitudinal musculature except portion of cirrus-pouch and 

 vagina. Eggs small, provided with three (?) membranes, outer one 

 gelatinous. 



Type of genus: — Crepidobothrium gerrardii (Baird) from Boa con- 

 strictor L. (type host) ; So. America (Brazil) (type locality). 



In the following table (pages 260-267) the principal data relating 

 to the species of Ophiotaenia and Crepidobothrium are brought together : 



