69] PROTEOCEPHALIDAE — LA RUE 69 



outline. The vitellaria are typical of the genus. The uterus is formed 

 of a median ventral-lying tube which extends nearly the full length of 

 the proglottid. From this tube, by the process described for Ophiotaenia 

 filaroides, lateral outpocketings arise. These lateral pouches (Fig. 92) 

 number 10-14 on either side. As the pouches become filled with eggs 

 the outlines of some of them are nearly obliterated. Yet in all but the 

 ripest proglottids the full number is visible. Sections through mature 

 and ripening proglottids show the pouches in all stages of development. 

 Sections also reveal the ventral diverticula which finally come to open 

 on the surface. Such diverticula were described in an earlier paper (La 

 Rue 1909:36) for Ophiotaenia filaroides and their presence in other spe- 

 cies was at that time noted. In P. pinguis the number of ventral diver- 

 ticula is greater than Gui. Schneider (1905) reported in P. macrocepha- 

 lus, P. percae, P. esocis, and P. ambiguus but smaller than the number 

 reported by the writer for 0. filaroides. A drawing (Fig. 89) of a 

 frontal section just below the cuticula shows two of these openings. In 

 such sections the openings, usually two or three, and the tubes leading 

 up to them could be readily traced. A specimen cleared in glycerine 

 showed these openings beautifully. The actual count of openings on 25 

 consecutive proglottids of this specimen is as follows : 1, 2, 3, 2, 2, 2, 1, 

 1, 2, 3, 2, 2, 2, 2, 2, 3, 2, 4, 3, 2, 4, 2, 3, 3, 3. The uterine eggs were 

 observed only in preserved condition. The outer mucilaginous envelope 

 could not be seen. The embryos measured 0.016-0.018 mm . 



Proteocephalus pinguis La Rue is a much larger form than P. esocis 

 (Gui. Schneider). It has a fifth sucker which the latter lacks. It dif- 

 fers from that species in having a larger head, larger suckers, larger 

 proglottids, more testes and a relatively shorter cirrus-pouch. P. pin- 

 guis differs from P. pusillus "Ward, a species occurring in the same local- 

 ity, in the possession of a larger head, larger suckers, larger proglottids 

 which have proportions different from those of P. pusillus. Moreover, 

 the segmentation is of a different character and the relative lengths of 

 the cirrus-pouches in the two worms are very different. P. pinguis dif- 

 fers very much from P. exiguus La Rue in size, in the proportions of the 

 proglottids, in the size of the head and of the suckers, in the relative 

 length of the cirrus-pouch, in the character of the uterine pouches and 

 in the size of the embryos. 



P. pinguis differs from P. macrocephalus (Creplin) in having a 

 fifth sucker, in being considerably smaller, in the relative length of the 

 cirrus-pouch, in the number of testes, and in the size of the embryos. 

 P. pinguis is smaller than P. ambloplitis (Leidy), P. singularis La Rue 

 and P. perplexus La Rue. There is also a difference in the size and 

 character of the head and suckers. It is further differentiated from 



