SEASONAL INFESTATION WITH LARVAL NEMATODI s. 50! 



body length 262 n and width 77 /JL; tail approximately same 

 length as body; ratio of tail stem to furcae about 3 : 2. Anterior 

 penetrating organ, a highly modified oral sucker, 51 /j. in greatest 

 diameter; ventral sucker much smaller. Eosinophilic head 

 gland observed in sections of anterior organ; ventral capillary 

 mouth and esophagus as in other members of group. Body 

 covered with short spines uniformly distributed; absent from 

 tail and furcae. Two eye spots composed of large pigment 

 granules, in posterior connection with nervous system. Most of 

 body filled with three differentiated sets of larval penetration 

 glands: one pair of cells, posterior to eye spots, with finely 

 granular cytoplasm, chromophobic in sections; two pairs of 

 glands, dorsal to ventral sucker, with coarsely granular eosino- 

 philic cytoplasm; three pairs of glands in posterior part of body, 

 with rod-filled cytoplasm, homogeneous in sections, staining 

 deeply with iron hematoxylin. No rapid selection of intra- 

 vitam neutral red or toluidine blue shown by any set; anterior 

 pair deeply stained, the two middle pairs chromophobic, and the 

 three posterior pairs lightly stained in very strong solution of 

 either dye. Five pairs of flame cells in body and one pair in 

 proximal tail stem; exact connections of two posterior body 

 flame cells not determined, but judging from fresh water larvae 

 for which excretory system is known pattern is probably like 

 that of C. wardi (Miller, 1923: Text-fig. 4); excretory system in 

 tail opening at tips of furcae. Cell mass representing future 

 reproductive system ventral and posterior to ventral sucker. 

 Development of cercaria within long sporocysts of uniform 

 diameter throughout, measuring on average 1.3 mm. in length 

 and 0.37 mm. in width and containing between twenty and thirty 

 cercariae. 



Cercaria variglandis is different in a number of respects from 

 the few described marine furcocercous larvae: C. dichotoma 

 Miiller 1850, C. discursata Sinitsin 1911, and C. syndosmyx 

 Pelseneer 1906. 



CERCARIA QUISSETENSIS sp. nov. 

 (Figs. 9, 11-14, 18, 19.) 



Echinostome cercaria with twenty-seven spines on collar. 

 Body averaging 290 fj. in length and 130^ in width (extreme 



