54 University of California Publications in Zoology. [Vol.8 



Genus Spadella Langerhans 

 Spadella draco Krolin 



PI. 2. fig. ]0; pi. 3, fig. 23; pi. 4, fig. 37. 



Spadella draco Krohn (1853), p. 273; Hertwig (1880), p. 71; Lan- 

 gerhans (1880), p. 136; Grass! (1883), p. 23; Kriimbach (1903), 

 p. 628; Fowler (1906), p. 25. 



Pterosagitta mediterranea Costa (1869), p. 55. 



Spadella vougai Beraneck (1895), p. 155. 



Characters 



Body firm and opaque (pi. 2, fig. 10), retaining its form well. Neck 

 absent. Collarette very pronounced, measuring in width appro.ximately 

 0.5 per cent on either side of the body. It extends from head to tail- 

 septum and, in the San Diego specimen, it spreads out over the anterior 

 part of the lateral fin. Muscles heavy and strong. Body, including 

 collarette, nearly of uniform width from head to tail-septum. Ventral 

 ganglion located about midway between tail-septum and head. Corona 

 ciliata two-thirds on head, long and elliptical in shape. Lateral fin semi- 

 circular in form. 



Vestibidar ridge (pi. 3, fig. 23) provided with a very few irregular 

 papillae. Notch extends to middle of second tooth. Even the tip of 

 first tooth is covered by the wing so that none are left entirely exposed. 

 External process terminates abruptly just beyond the first tooth. It com- 

 prises about 26 per cent of the length of the entire ridge. 



The seizing jaws (pi. 4, fig. 37) of the single specimen from San Diego 

 bear out Krumbach 's (1903) description. The points have an oval base, 

 and are inserted about one-fourth or one-fifth their height into shaft. 

 They are strongly needle-shaped. Pulp-canal central. Upper third of 

 shaft strongly bent. Flat broad-edged crest along edge of shaft. 



But one individual of this species was taken. It offers the 

 following measurements : 



Length 7 mm. 



Width 12.1 per cent 



Width without collarette 10.9 per cent 



Tail 43.6 per cent 



Tail to ventral ganglion 66 per cent 



Lateral fin 21.2 x 5.4 per cent 



Seizing jaws 8-? 



Anterior teeth 4-4 



Posterior teeth 9-8 



The number of teeth and seizing jaws scarcely agrees with 

 that reported b.y Krohn (1853) or Hertwig (1880). They record 

 the seizing jaws as 10, anterior teeth 8, posterior teeth 18, while 

 our specimen agrees more nearly with Beraneck 's (1895) descrip- 



