390 bulletin: museum of comparative zoology. 



Corresponding to the flattening of the body, the subventral ribs of 

 each pair lie close together, the subtentacular further apart. The 

 sexual products occupy the meridional canals only so far as the ends 

 of the ribs, and where they occur the margins of the canals are very 

 slightly lobed. In Moser's specimens the cilia of the stomach agree 

 with those of P. pandorina, i. e., they are unusually stout and long, 

 and there was no " Wimperschnur um den Mund." So far as I can 

 judge from surface views with the microscope, the conditions are the 

 same in the "Albatross" specimens. Certainly there is no visible 

 band of cilia surrounding the mouth; and wherever a few gastric 

 cilia can be distinguished they are remarkably stout. But for the 

 most part they are gone. 



To judge from the three records of this species, Japan (Moser), 

 west coast of South Africa (Moser), and the Eastern Tropical Pacific, 

 it is very constant in character. All the older specimens agree in 

 having unequal ribs, and in their arrangement in pairs, in general 

 form and proportions, in having a large mouth, in the type of branch- 

 ing of the meridional, and simplicity of the gastric canals ; and in the 

 limitation of the sexual products to the portions of the canals occupied 

 by the ribs. The present capture is interesting from the standpoint 

 of geographical distribution, as showing its wide dispersal over the 

 Pacific, and that it occurs there on both sides of the Equator. In the 

 Atlantic it is so far known only from lat. 32° 5' S., long. 8° 30' W.; 

 between Ascension and St. Helena, and from near Cape Town (Moser, 

 : 09). But its general resemblance to a Beroe is so great that it might 

 easily be overlooked by anyone but a specialist. 



LOBATA. 



BOLINOPSIDAE nom. nov. 



Bolinopsis L. Agassiz. 



While the " Albatross" lay at anchor in Acapulco Harbor I was able 

 to study, in life, a large and beautiful Bolinopsis, 1 of which several spec- 

 imens were taken. Moser has recently attempted a revision of this 

 genus, and done much to bring order out of confusion, though the 

 relationships of the several forms recorded from tropical regions are 



» Bolina is preoccupied for a mollusc (Mayer, :12, p. 20). 



