250 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



< i-l 0* Oi iO r-teO 



a a a a a a a a 



BB5IBS 



Distribution. S. serratodentata was 

 collected from only eight stations. All 

 except three were mesoplanktonic, but 

 the largest number of specimens (73) 

 were taken from the surface. The rec- 

 ords are given in Table 6 : 



SAGITTA MACROCEPHALA Fowler. 



Sagitta macrocephala FOWLER (1905), p. 65. 

 RITTER-ZAHONY (1911), p. 31. 



A single distorted specimen was ob- 

 tained. Its measurements follow: 



Length in mm 7.8 mm. 



Width in per cent of length 14.4 per cent. 



Tail in per cent of length 37. 4 per cent. 



Length of posterior fin 24. 8 per cent. 



Per cent of fin in frontof tail- 

 septum 45.5 percent. 



Width of posterior fin 7 . 7 per cent. 



Interval from anterior to posterior 

 fin 5.5 per cent. 



Length of anterior fin 15.0 per cent. 



Width of anterior fin 2. 7 per cent. 



Number of anterior teeth 7-7 



Number of posterior teeth 25-26 



Number of seizing jaws 11-11 



Ventral ganglion, corona ciliata, and 

 ovaries not observed. 



The specimen differs conspicuously 

 in width from those drawn by Fowler 

 (1905, pi. 5, fig. 16) and Ritter-Zahony 

 (1911, fig. 37). In width the Philip- 

 pine specimen measures 14.4 per cent 

 of the length, while Fowler draws it 

 7.8 per cent, and Ritter-Zahony 5 per 

 cent. However, the Philippine specimen 

 is clearly immature, neither ovaries nor 

 seminal vesicles being visible. More- 

 over, it is poorly preserved, some 

 portions of the body being distorted 

 and others torn away. These facts 

 are probably responsible for the ex- 

 cessive width. Unfortunately the points 

 of all' seizing jaws were broken off, 

 so that their structure could not be 

 determined. 



