270 
PACIFIC SCIENCE, Vol. XIII, July 1959 
Fig. 1. Zooplankton stations occupied on Eastropic Expedition. Stars indicate stations occupied by RV Hori- 
zon; circles indicate those occupied by RV Spencer F. Baird. Modified from Holmes, Schaefer, and Shimada 
( 1957 ). 
Dana, Discovery, and Shellback expeditions), 
but published works considering the Chae- 
tognatha from the area are very few. Of the 
36 species considered valid by Tokioka 
(1952), the following 18 species have been 
recorded by Baldasseroni (1915), Michael 
(1908, 1911), and Bieri (1957): Sagitta hedoti, 
S. hipunctata = californica, S. decipiens, S. enflata, 
5. ferox, S. hexaptera, 5. lyra, S. minima, 5. 
neglecta, S. pulchra, S. regularis, S. robusta, 5. 
serratodentata, S. tenuis, Krohnitta pacifica, K. 
suhtilis, Eukrohnia hamata, and Pterosagitta 
draco. 
In addition to these species, 5. serratodentata 
pacifica and S. pseudoserratodentata have been 
identified from the Eastropic material. 
ice, Honolulu, T. H. Of these, only those 
species represented in the Eastropic collec- 
tions are considered in this publication. The 
armature formulae are included in this paper 
as they have been found useful in determining 
the variability within the limits of each spe- 
cies and in verifying the identity of juvenile 
and damaged specimens. Eor the measure- 
ments of the total length of the body and the 
tail segment, the caudal fin has been excluded 
as it is often damaged and its inclusion would 
lead to error. 
DESCRIPTION OF THE SPECIES FOUND 
IN EASTROPIC COLLECTIONS 
Several oceanographic investigations of the 
eastern Pacific have been made (Albatross, 
