334 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



The eastern Pacific series (Bigelow, 1911&) showed that the re- 

 markable eudoxid Ceratocymba asymmetrica Lens and Van Riems- 

 dijk is the free eudoxid of A. leuchartii. Ceratocymba sagittata 

 Quoy and Gaimard is the eudoxid of Diphyabyla hubrechti Lens and 

 Van Riemsdijk (Bigelow, 1918; Moser, 1911, 1912). 



Though the superior nectophore of A. leuckartii is so character- 

 istic that it is not likely to be mistaken for any other species, it has 

 seldom been recorded. The Siboga took it at five stations ; the Alba- 

 tross at seven in the eastern Pacific. Agassiz and Mayer (1902) de- 

 scribe it from the Marquesas and from near the Paumotas. Huxley's 

 original specimen was taken off the east coast of Australia. I have 

 recently recorded it from the West Indies (Bigelow 1911&, 1918) ; 

 Moser (1913) from the Atlantic. 



ABYLA TRIGONA Quoy and Gaimard. 



Abyla trigona Quoy and Gaimard, 1827, p. 14, pi. 2B, figs. 1-8. 

 Bigelow, 1911b, p. 221. 



Abyla trigona — material examined. 



Synonymy, 



The superior nectophores are all in fair condition, but only two of 

 the five inferior ones (station 5672) preserve their normal outlines. 



All of the specimens show the conformation of facets and ridges 

 characteristic of trigona, as opposed to the closely related haeckcli 

 Lens and Van Riemsdijk. The difference has been discussed else- 

 where (Bigelow, 1911b). Briefly stated, it consists in the presence 

 of a transverse ridge in the superior nectophore of haeckeli, which 

 divides the single dorsal facet, such as is seen in trigona, into two 

 facets. A very detailed description has been given by Lens and Van 

 Riemsdijk. 



A. trigona or its eudoxid was taken at 18 stations by the Siboga, 

 and it is also known from the Indian Ocean, so it was to be expected 

 in Philippine waters. 



ABYLOPSIS TETRAGONA (Otto) Bigelow. 



Pyramis tetragona Otto, 1823, p. 306, pi. 42, figs. 2ff-2e. 

 low, 1911b, p. 224. 



Synonymy, Bige- 



This species has usually been known as Abyla pentagona Quoy and 

 Gaimard. The use of the name tetragona rests on Chun's statement 



