396 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



Echinostephanus hispidus was collected by Yamaguti from Seriola 

 quinqucradiata from Japan (Pacific Coast). Ward (1937, p. 517) 

 pointed out that the genus Echinostephanus should be considered a syno- 

 nym of Stephanochasmus (= Stephanostomum). There can be no doubt 

 as to this synonymy. 



An interesting but perplexing condition exists among the specimens 

 from the 3 species of Seriola mentioned above. Specimens from any one 

 of these species are remarkably similar but differ in small details from 

 specimens collected from any of the other species of Seriola. One rather 

 obvious solution, if the differences are not sufficient to warrant different 

 species, is to consider that 3 subspecies or varieties exist. Certainly on the 

 basis of available specimens (which include 4 specimens collected by 

 Yamaguti and kindly sent to the writer), certain fairly constant but 

 slight differences exist among the 3 collections. It was decided, however, 

 not to give specific rank to each collection. 



Figs. 79 and 80 show the form from 5. dorsalis. In this form the 

 suckers are usually subequal, but in one specimen the ratio was almost 3 :4 

 (0.225 as compared with 0.277) . The number of oral spines was 42 to 44 

 (possibly 46 in one specimen). The oral spines are noticeably smaller 

 ventrally, and about 7 lateral spines on each side lie in a single row (fig. 

 80). This unusual arrangement was described by Yamaguti for S. hispi- 

 dum. He states, "There are 42 spindle-shaped spines arranged dorsally 

 and ventrally in two alternate rows, but laterally in a single row." His 

 figures do not show this condition clearly, and specimens I have are some- 

 what macerated and without spines. Other characters of interest shown 

 by the form from S. dorsalis are : long genital atrium extending posterior 

 to the acetabulum, anterior limit of the vitellaria either at the base of the 

 cirrus sac or as far forward as the anterior level of the seminal vesicle 

 (about ys the length of the cirrus sac), and conspicuous metraterm al- 

 most as long as the cirrus sac. 



Specimens from Seriola species agree in most respects. The oral spines 

 are the same number (about 44), but the single lateral row is less evident 

 and apparently not present in some if in any of the 6 specimens. The oral 

 sucker is not equal to the acetabulum, the ratio being about 3 :4 or even 

 2 :3. This sucker ratio, however, is not much different from that shown by 

 one specimen from S. dorsalis. The only other difference is that the ovaiy 

 is separated from the testes by at least a few vitelline follicles. In this 

 respect, the form resembles Yamaguti's specimens. 



