BIGELOW: THE CTENOPHORES. 



391 



still unsettled. Moser agrees with Vanhoffen ('95) that the north 

 Atlantic infundibulum and (data, and the Behring Sea septetitrionalis 

 all belong to one species of circumpolar distribution. This view seems 

 to me thoroughly in accord with the various published figures and 

 descriptions, and my own studies of living specimens from the coasts 

 of New England lead me to adopt it without hesitation. The best 

 figures of the New England form are those by L. Agassiz ('49); of 

 the north European by Vogt ('88). B. infundibulum is the only 

 species which is known from more than very few records ; and even for 

 it the normal limits of variation are still to be traced. Under these 

 circumstances it is very difficult, perhaps impossible, to reach a 

 sound conclusion as to the relationships of the various other species. 



The following are listed by Moser ( : 08a) : — hydatina Chun from 

 the Mediterranean, elegans Mertens from the " South Seas," chuni 

 von Lendenfeld from south Australia, vitrea L. Agassiz ('60) from the 

 southeastern coasts of the 

 United States, ovalis Bigelow 

 ( : 04) from the Maldive Islands 

 and mikado Moser (:07, :08a) 

 from Japan. And to show how 

 little we know about them, I 

 may point out that ovalis and 

 mikado were each described from 

 a single fragmentary specimen, 

 elegans from a single record in 

 1827, and vitrea from very few 

 records. 



The Acapulco specimens agree 

 most closely with the accounts 

 of vitrea, and particularly with 

 Mayer's figures of that species. 

 Like the latter they are compar- 

 atively slender in outline, the 

 lappet-canals are but little con- 

 voluted, and the auricles are 

 short. The only differences are 

 that in our largest specimen (82 

 mm. long) the lappets are pro- 

 portionately slightly shorter 

 than Mayer shows them, that 



the sub ventral ribs extend further over the lappets (Eig. A), and that 

 the canals and tentacular apparatus were amber-yellow instead of being 



Fig. A. BoHna vitrei. Specimen from 

 Acapulco, 82 mm. long. After a drawing 

 from life. The musculature of the inner 

 surface of the lappets is omitted. 



