1911] Michael: Chaetognatha of the San Diego Region. 75 



The similarity of this species to (S*. neglecta has already been 



considered in detail. Ritter-Zahony (1909b) says: "Bei gut 



erhaltenen Individuen ist allerdings die ausserordentlich machtig 



entwickelte Collarette mit den stark vorspringenden Tasthiigeln 



das beste Erkennungsmerkmal, haiifig bemerkt ich jedoeh, dass 



sie infolge der Konservierung verloren gegangen oder stark 



geschrumpft war." 



Collarette conspicuous, extending to anterior fins. Head small. 

 Muscles broad and stout. Body firm, opaque, and of about the same 

 width from ventral ganglion to seminal vesicles. Anterior fins shorter 

 and narrower than posterior fins, extending nearly to ventral ganglion. 

 Posterior fins widest behind tail-septum, and extending to seminal 

 vesicles. Less than 50 per cent of posterior fin in front of tail-septum. 

 Anterior teeth 2-4. Posterior teeth 2-7. Seizing jaws 6-9. Tail 28-40 

 per cent of total length. 



Sagitta pulchra Doncaster 



Doncaster (1902b), p. 213. 



Fowler (1906), p. 17, pi. 2, figs. 49-54. 

 Collarette present. Body very transparent, slender, and firm. Widest 

 about one-half to three-fourths distance from head to tail-septum, taper- 

 ing gradually forward, and more rapidly backward. Anterior fins longer 

 and narrower than posterior fins, the anterior fourth consisting of 

 epidermic thickening with but few rays. Posterior fijis widest at, or 

 behind, tail-septum, barely extending to seminal vesicles. More than 50 

 per cent of posterior fin in front of tail-septum. Vestibular ridge with 

 sharp, regular papillae, and provided with a very strong external process. 

 Corona ciliata long, commencing between eyes and extending one-half 

 distance from head to ventral ganglion. Anterior teeth 5-10. Posterior 

 teeth 9-15. Seizing jaws 5-7. Tail 18-27 per cent of total length. 



Sagitta bedoti Beraneck 



Beraneek (1895), p. 137. 



Fowler (1906), pp. 6-8, pi. 1, figs. 1-8. 

 Collarette absent. Head small. Lateral fields large. Muscles strong 

 but narrow. Body firm, transparent, and widest at middle of length, with 

 sudden diminution at tail-septum. Anterior fin longer than posterior fin, 

 extending nearly to ventral ganglion. Posterior fins broader than an- 

 terior fins, widest behind tail-septum, and extend to seminal vesicles. 

 Less than 50 per cent of posterior fin in front of tail-septum. Papillae 

 of vestibular ridge regular and acute. External process long and sharp. 

 Anterior teeth 5-13. Posterior teeth 16-32. Seizing jaws 5-7. Tail 21-35 

 per cent of total length. 



Sagitta macrocephala Fowler 

 Fowler (1905). p. 65, pi. 5, figs. 16-21. 

 Collarette absent. Head unusually large. Neck narrow and jjromi- 



