258 
PACIFIC SCIENCE, Vol. XI, July, 1957 
Fig. 4. Occurrence of Pterosagitta draco off Peru in 
1941. (Number per five-minute surface tow, one-half 
meter net.) 
Whether or not this difference is a seasonal 
one can only be shown by repeated short 
interval sampling over a period of several 
years. It can be said, however, that the pres- 
ence of the species closer to the coast in 1941 
could be due to greater penetration of south 
Pacific central water from the west towards 
the coast in 1941 or greater southern penetra- 
tion of equatorial water from the north. 
Sagitta bedoti occurred sporadically in low 
numbers at 14 stations (Fig. 6) with the great- 
est numbers in the north. It was found in the 
nearshore region of Peru in 1952 but appears 
to have penetrated further south in 1941. 
Immature specimens of what appeared to 
be Sagitta calif ornica were found at four stations 
(a single specimen at stations 14, 18, and 9 
and three specimens at station 17). This spe- 
cies is widespread in the Pacific, occurring 
from roughly 38 degrees north to 38 degrees 
south; however, it is missing or extremely 
rare in the equatorial region (about 5 degrees 
north to 5 degrees south) and is missing from 
most of the California current. It is not com- 
mon near shore except during unusual con- 
ditions such as reported by Michael in 1913. 
It was present at only one station off Peru in 
1952 (14°01'S, 81°47'W) but was common 
north of the equator at that time. It appears 
most likely that the specimens in 1941 came 
from the north although the possibility of an 
intrusion from the southwest of Peru cannot 
be definitely ruled out. 
Sagitta enflata (Fig. 7) occurred at all but 
three of the 1941 stations. Its distribution in 
Fig. 5. 1941 distribution of Krohnitta pacifica com- 
pared to 1952. Crosses with hatchure— present 1952, 
without hatchure — absent 1952. 
