BIGELOW: MEDUSAE AND SIPHOXOPHORAE. 409 



surface and intermediate hauls. The material consists of two entire 

 specimens and fifteen superior nectophores, and two eudoxids. 



Abyla leuckartii Huxley. 



Abyla leuckartii Huxley, 1859, p. 49, pi. 3, fig. 2; Agassiz & Mayer, 1902, p. 16-5 

 {partim); Lens & Van Riemsdijk, 1908, p. 34, pi. 5, fig. 42-46; Bigelow, 

 1911b, p. 216, pi. 13, fig. 5-8, pi. 15, fig. 3, 4; Moser, 1913a, p. 149. 



Enneagonum leuckartii Schneider, 1898, p. 93. 



Station 10,194, 100- meters, one superior nectophore, 6 mm. long. 

 The identity of this specimen rests on actual comparison with speci- 

 mens from the West Indies, and from the Pacific (1911b). 



Abyla dentata, sp. nov. 

 Plate 5, fig. 1-i. 



Station 10,166, 100-0 meters, one superior nectophore. Extreme 

 length (apical margin to tip of basal tooth), 14 mm. Type. 



Station 10,171, 75-0 meters, one superior nectophore, badly dis- 

 torted. 



These large nectophores evidently belong to the A. trigona-lcuckariii 

 group, i. e., are true Abyla, in the restricted sense (1911b, p. 213). 

 But they differ so much from all described species in the arrangement 

 of ridges and facets, as to necessitate a new species. Like A. leuckartii, 

 the nectophore is pentagonal in side view, its upper portion rectangular 

 (Plate 5, fig. 1); but it is much thicker than that species, a fact which 

 gives it a characteristic cubical appearance. The facets are essentially 

 the same as those of A. leuckartii, i. e., apical, dorsal, ventral, dorso- 

 lateral, and ventrolateral. The most diagnostic feature of this new- 

 species is the dorsal facet of its superior nectophore. In all other 

 Abylas, i. e. A. leuckartii, A. trigona, and A. haeckeli, this is rectangular. 

 But in A. dentata it is essentially triangular (Plate 5, fig. 3), its apex 

 apical, its base deeply emarginate, with its lateral margins strongly 

 bowed, and very prominently toothed in the lower f of their length. 



The ventral facet (Plate 5, fig. 2) at first sight suggests A. trigona 

 (1911a, pi. 13, fig. 4), being similarly pointed basally, and emargi- 

 nate laterally near its upper end, while lacking the transverse ridge 

 which subdivides it in A. haeckeli. But instead of being Hmited 

 apically b}- a distinct apico ventral ridge, as is the case in A. leuckartii, 

 A. trigona, and A. haeckeli, it is continuous here with the apical ridge, 



