146 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 39. 



one lobe often projecting over the lateral excretory canals near the 

 genital pore; and, in the region of the gravid proglottids, a large trans- 

 verse excretory canal occupying a position directly between proglottids. 



In compiling a key to the dog tapeworms, an examination of 

 Kholodkovski's (1908) description and figures of Tsenia punica from 

 the dog showed that the cestode in question probably belongs in the 

 genus Proteocephalus Weinland. The head, the uterine stem, the 

 position of the ovaries at right angles to the uterine stem, and the 

 position of the testes and the genital canals all indicate this. The 

 granular strand of uncertain nature which Kholodkovski noted in 

 the position of the excretory canals can hardly be anything other 

 than the vitellaria, in the location usual for species of the genus 

 Proteocephalus. Kholodkovski states that the vitellarium is very 

 small, but it seems Hkely that he has mistaken something else for the 

 vitellarium. A comparison of the figures with mounted specimens 

 of worms of the genus Proteocephalus leaves no reasonable doubt on 

 this point, and it is the opinion of the writer and Dr. B. H. Ransom, 

 with whom the pomt was discussed, that it is more likely that the dog 

 from which the tapeworms were obtained had just eaten the true 

 host, some fish, reptile, or batrachian, than that the dog was the 

 true host by virtue of a normal, even though unusual, infection with 

 larval form. Fuhrmann appears to have overlooked the unusual 

 features of this worm in his review of Kholodkovski (1909), and states 

 that the anatomy is that of species of Tsenia. 



The desirability of removing this species from the genus Tsenia at 

 once raises the question as to whether it shall take the generic name 

 Proteocephalus Weinland (1858) or Icthyotxnia Lonnberg (1894). 

 The writer and Doctor Ransom have gone over the literature of this 

 subject and base a preference for the name Proteocephalus on the 

 following points. 



Weinland (1858) proposes the genus Proteocephalus in a footnote 

 in the following terms : 



Proteocephalus Weinl. . . . The shape of the head in this genus is extremely 

 variable. There is no proboscis, nor booklets. The eggs are provided with two shells, 

 the outer shell being mucilaginous. These Taenioids live in reptiles and fishes. The 

 type of the genus is Taenia ambigua, Dujardin. Here belong Taenia filicollis and T. 

 dispar. 



Lonnberg (1894) proposed for the fish tapeworms the generic name 

 Ichthyotsenia, noting for this genus the following characteristics : The 

 vagina opens beside and anterior to the cirrus pouch, and the vitellaria 

 are peripheral and follicular. As type of the genus he names the 

 following species in the order given: Icthyotxnia filicoUis (Rudolphi), 

 I. ocellata (Rudolphi), I. longicollis (Rudolphi), /. torulosa (Batsch), 

 and /. coryphicephala (Monticelli) . 



I 



