76 University of California Pnhlications in Zoology. [Vol.8 



nent. Lateral fields small. Body slender, firm, opaque, and widest at 

 middle of length. Anterior fins shorter and narrower than posterior fins, 

 never extending to ventral ganglion. Posterior fins about equally divided 

 between body and tail, but usually with more than 50 per cent in front 

 of septum. Vestibular ridge with thick cuticle and provided with 

 irregular papillae, which are fewer in number than posterior teeth. 

 Anterior teeth 5-10. Posterior teeth 12-33. Seizing jaws 9-12, very 

 sharply curved in the distal fourth. Tail 29-41 per cent of total length. 



Sagitta gazelle Ritter-Zahony 

 Eitter-Zahony (1909c), p. 788. 

 The characters of this species have already been considered in con- 

 nection with the description of S. lyra (pp. 32-39). As the description 

 given by Ritter-Zahony is incomplete, I can add nothing to my former 

 remarks. 



Eukrohnia pacifica (Aida) 



Aida (1897), pp. 19, 20, tab. 3, fig. 11. 



Fowler (1906), p. 24, pi. 3, figs. 81-85. 

 Collarette absent. Head medium. Neck fairly evident. Body slender, 

 about 5 per cent in width, but broader than in E. subtilis. Widest about 

 midway between ventral ganglion and tail-septum, tapering gradually in 

 both directions. Lateral fins arise nearly two-thirds distance from ven- 

 tral ganglion to tail-septum, and terminate at seminal vesicles. Usually 

 slightly less than 50 per cent of fin in front of tail-septum, its point of 

 greatest width being behind septum. Corona ciliata short, clove-shaped, 

 extending onto head but never reaching eyes. Teeth "bayonet-shaped" 

 springing from a narrower neck than in E. subtilis, the number varying 

 from 11 to 16. Seizing jaws, 6-9, with back of shaft made up of two curves, 

 the junction of which makes an obtuse angle at a point about one-fourth 

 the length of jaw proximad of tip. Tail 25-41 per cent of total length. 



Spadella cephaloptera Buseh 



Busch (1851), pp. 93-100. 



Hertwig (1880), pp. 66-67, taf. 1, fig. 6. 



Fowler (1906), p. 34, pi. 3, figs. 95-99. 

 Collarette massive, widest just behind head, but less than half the 

 width of body. Head medium. Neck evident. Collarette extends to 

 tail-septum, where it becomes continuous with lateral fin. Body firm and 

 opaque. Lateral fin more than five times longer than wide, extending 

 to seminal vesicles. Corona ciliata confined to neck, its long axis being 

 transverse to the body and extending over the collarette. Anterior teeth 

 3-4, irregularly set and blunt, the innermost being very long. Posterior 

 teeth 3-4. Seizing jaws 8-9, slender and slightly saginate. Tail 50 per 

 cent of total length. 



