74 University of California Puhlications i)i Zoology. [Vol.8 



gazelle, Eukrohnia pacifica and Spadella cephaloptera. Owing 

 to the inadequacy of descriptions, and the impossibility of ob- 

 taining authenticated specimens, iS. minima is not considered. 



Sagitta decipiens Fowler 



Fowler (1905), p. 70, pi. 5, figs. 32-35. 

 Collarette present, but very short. Body transparent, firm, slender, 

 and widest behind middle of length, tapering gradually toward each end. 

 Neck not well marked. Anterior fin shorter and narrower than posterior 

 fin, not extending to ventral ganglion. Posterior fin widest at or just 

 behind tail-septum. More than 50 per cent of posterior fin in front of 

 tail-septum. No diminution at tail-septum. Ovary short and thick. Ova 

 large. Vestibular ridge prominent, with thick cuticle and long external 

 process sometimes forked. Anterior teeth 5-10. Posterior teeth 12-18. 

 Seizing jaws 5-6. Tail 25-40 per cent of total length. 



Sagitta sibogae Fowler 

 Fowler (1906), p. 12, pi. 2, figs. 66-72. 

 Collarette present, but short. Body firm, opaque, and widest at 

 middle point, tapering gradually forward andmore rapidly backward. 

 Head large. Neck large. Lateral fields medium. Muscles strong. An- 

 terior fins longer and narrower than posterior fins, extending to ventral 

 ganglion. Posterior fins widest at plane of tail-septum, with slightly 

 more than 50 per cent in front of tail-septum. It never extends to 

 seminal vesicles. Vestibular ridge with numerous large and fairly 

 regular papillae. Anterior teeth 7-11, short with broad bases. Posterior 

 teeth 13-23. Seizing jaws 5-7. Tail 21-33 per cent of total length. 



Sagitta ferox Doncaster 



Doncaster (1903), p. 212. 



Fowler (1906), p. 10, pi. 1, figs. 18-23. 

 Collarette present, extending to anterior fins, and exceptionally wide. 

 Head large. Lateral fields small. Muscles broad and thick. Body firm, 

 broad, opaque, and nearly of uniform width from in front of ventral 

 ganglion to tail-septum. Anterior fins longer than posterior fins, extending 

 to ventral ganglion. Posterior fins about same width as anterior fins, 

 extending to seminal vesicles. Less than 50 per cent of posterior fin in 

 front of tail-septum. ' ' Vestibular ridge strongly mammillated, terminat- 

 ing externallj' in a very blunt process. ' ' Corona ciliata long, commencing 

 in front of eyes and terminating near ventral ganglion. Anterior teeth 

 4-10, closely set, and with broad bases. Posterior teeth 9-14, long, broad, 

 closely set, and diverging distally. Seizing jaws 5-6. Tail 26-36 per 

 cent of total length. 



Sagitta regularis Aida 

 Aida (1897), p. 18, tab. 3, fig. 1. 

 Doncaster (1902b), p. 211. 

 Fowler (1906), p. 18, pi. 2, figs. 55-58. 

 Eitter-Zahony (1909b), fig. 7. 



