260 
PACIFIC SCIENCE, VoL XI, July, 1957 
Fig. 8. Distribution of Sagitta ferox in 1941 and 
1952. Crosses are 1952 stations. S. ferox was absent 
from all 1952 stations. 
Fig. 9- Occurrence of Sagitta hexaptera off Peru in 
1941. 
seem somewhat anomalous since it occurs 
together with equatorial species. Its distribu- 
tion together with that of S. minima indicates 
complex conditions between stations 14 and 
23. 
Single specimens of Sagitta minima were 
taken at stations 22 and 19 while five speci- 
mens were taken at station 18 and three speci- 
mens at 16. This species has a widespread but 
irregular distribution in the Pacific and is 
most abundant in cool offshore waters. It 
occurred sporadically off Peru in 1952. 
A single specimen of Sagitta neglecta was 
taken at station 17. In 1952 S. neglecta did not 
occur south of about three degrees south 
latitude; thus the present record indicates 
some southward penetration of equatorial 
water. 
Sagitta regularis (Fig. 10) had a distribution 
similar to K. pacifica and S. ferox in 1941 and 
occurred considerably inshore of its limits in 
1952. It could have reached this position by 
intrusion of water from the north or west. 
Sagitta robusta (Fig. 11) apparently was 
more common off Peru in 1941 than in 1952. 
Since this species is most abundant in warm 
waters, it indicates warmer water present off 
Peru in May 1941 than in August 1952. 
The Sagitta serratodentata group is here split 
into two populations provisionally called Sa- 
gitta pacifica (Furnestin, 1953) and Sagitta sp. 
S. pacifica has a distribution similar to P. 
draco , S. enflata , and S. hexaptera and is found 
at nearly every station in 1941 (Fig. 12). 
Sagitta sp. is apparently new to science and 
will be described in a future publication. It 
