278 
PACIFIC SCIENCE, Vol. XIII, July 1959 
BODY LENGTH 
LENGTH OF TAIL 
ANTERIOR 
POSTERIOR 
IN MM. 
SEGMENT (IN °/o OF 
HOOKS 
TEETH 
TEETH 
TOTAL BODY LENGTH) 
Tokiokas specimens: 
15.8 
17.1 
6 
5 
10 
15.6 
23.1 
6 
8 
14.3 
16.1 
6 
7 
10 
12.9 
18.6 
6 
6 
11 
9.4 
20.2 
6 
6 
10 
9.3 
22.6 
6 
6 
9 
7.8 
23.1 
6 
6 
10 
Sagitta regularis Aida, 1897 
S, regularis, Bieri, 1957 
Body firm, moderately opaque. Tail segment 29-34 per cent 
of total length; hooks 7-8; 
anterior teeth 2-4; 
posterior teeth 4-7. Anterior fins start at posterior end of ventral ganglion. 
Small interval between anterior and posterior fins 
. Posterior fins wider than anterior fins. Vol- 
uminous collarette 
usually present, covering head and most of body. No intestinal diverticula. 
BODY LENGTH 
LENGTH OF TAIL 
ANTERIOR 
POSTERIOR 
IN MM. 
SEGMENT (in °/o OF 
HOOKS 
TEETH 
TEETH 
TOTAL BODY LENGTH) 
Eastropic specimens: 
5.8 
32.8 
7 
3 
5 
5.6 
32.1 
8 
4 
6 
5.3 
32.1 
8 
3 
5 
5.2 
30.8-32.7 
7 
3-4 
4-6 
5.1 
31.4 
8 
4 
7 
5.0 
32.0-34.0 
7 
2-4 
4-5 
4.8 
29.2-31.3 
7-8 
3 
5 
Sagitta robusta Doncaster, 1903 
S. robusta, Baldasseroni, 1915; Bieri, 1957 
Body very opaque, firm; of uniform width from neck to tail-septum. Tail segment 24-28 
per cent of total length; hooks 5-7; anterior teeth 6-11; posterior teeth 8-15. Anterior fins 
start at posterior end of ventral ganglion. Posterior and caudal fins both reaching seminal 
vesicles. Seminal vesicles long-tapered posteriorly. Ovaries long (when fully mature they may 
extend to the neck), containing eggs of moderate size. Intestinal diverticula present, but 
specimens are 
often too opaque for them to be seen. 
BODY LENGTH 
LENGTH OF TAIL 
ANTERIOR 
POSTERIOR 
IN MM. 
SEGMENT (in °/o OF HOOKS 
TOTAL BODY LENGTH) 
TEETH 
TEETH 
Eastropic specimens: 
13.7 
25.6 
7 
8 
8 
