NO. 14 MANTER : DIGENETIC TREMATODES OF FISHES 331 



The genus Lobatostoma was named by Eckmann in 1932. The 

 word Lobatostostoma (Eckmann, 1932, p. 396) is a synonym, the error 

 in spelling being obviously typographical. The genus contains L. ringens 

 (Linton) and L. kemostoma (MacCallum and MacCallum). 



SPECIFIC DIAGNOSIS OF LOBATOSTOMA PACIFICUM 



Total body length 2.632 to 4.279. Forebody, which may be more or 

 less retracted dorsal to the disc, 0.352 to 0.862. Anterior end with 2 large 

 ventral lobes and 3 dorsal lobes, the median of which is smaller than 

 the others. Ventral disc 1.552 to 2.160 in length or slightly less to slightly 

 more than Yz total body length. Full width of disc seen in only one 

 specimen where the disc was 1.755 long and 1.215 wide. Number of 

 marginal loculi almost always 32. In one of 12 specimens it was 34, 

 and in another it was possibly 31 (Bychowsky and Bychowsky, 1934, 

 have indicated some variation in number of locules in the disc of Aspido- 

 gaster species). Median loculi 15, each divided by a more or less incon- 

 spicuous median longitudinal ridge. Total number of loculi, therefore, 

 62 to 64. Marginal sense organs present between marginal loculi. Hind- 

 body (posterior to disc) 0.810 to 2.562, always more than ^ length of 

 disc, sometimes somewhat longer than disc ; posterior end of body tapered 

 almost to a point. Prepharynx 0.247 to 0.465; pharynx cylindrical 0.144 

 to 0.170 long by 0.100 to 0.127 wide; esophagus short; cecum reaching 

 about to posterior edge of disc or slightly beyond, not reaching posterior 

 end of body by some distance. 



Genital pore muscular, slightly to the left, just anterior to disc, 

 opposite esophagus or base of pharynx. Testis single, large, ovoid, longer 

 than wide, dorsal to disc (in one of 52 specimens it was posterior to the 

 disc). Cirrus sac (fig. 2) ovoid with thick wall of loose fibers, con- 

 taining a few gland cells and surrounded by gland cells ; seminal vesicle 

 tubular, free, much coiled, extending backward as far as ovarian level. 

 Ovary pyriform with its narrowed (posterior) portion recurved an- 

 teriorly; oviduct extends backward; Laurer's canal long, extending 

 backward, its termination not determined. Vitellaria in 2 lateral rows 

 from near anterior end of disc to end of cecum. Uterus extending to 

 near posterior end of body; uterine seminal receptacle present; metraterm 

 muscular, cylindrical, slightly shorter than cirrus sac, surrounded by 

 gland cells; just posterior to metraterm is a thin-walled, somewhat coiled 

 portion of the uterus, possessing a few gland cells in its wall (fig. 2). 

 Eggs 65 to 76 by 34 to 42 /x, usually 70 to 73 by 37 to 41 /i. The short 



