616 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 113 
considered unusual and perhaps abnormal in Clipperton material. 
After examining the syntypes of Hippolysmata paucidens Rathbun 
from the Hawaiian Islands, L. B. Holthuis (personal communication) 
concluded that that species should be synonymized with Lysmata 
trisetacea, as he had suggested in 1947. 
Comparison of the three males, eight ovigerous females, and one 
cephalothorax from the Hawaiian Islands with the Clipperton speci- 
mens disclosed minor, but possibly significant, differences. In three 
of the Hawaiian specimens, the posterior ventral rostral tooth is 
behind or opposite the anterior dorsal tooth; in all but two of the 
Clipperton specimens both ventral teeth, when present, are well in 
advance of the anterior dorsal tooth. All of the Hawaiian specimens, 
in which the carapace measures from 2.6 to 3.6 mm. in males and from 
4.0 to 4.8 mm. in females, have the fused part of the upper antennular 
flagellum not much shorter than the free portion of the shorter 
branch; in Clipperton specimens of comparable size, the fused portion 
is at most little more than half as long as the free portion and it may 
be no more than a third as long. The number of segments in the car- 
pus of the second pereiopods varies from 21 to 25, and averages more 
than 23 in the Hawaiian material, as opposed to a range of 19 to 24 
and an average of less than 21 in the Clipperton specimens. It is 
very possible that the Clipperton form is at least subspecifically 
distinct but, in view of the variation recorded in the literature for 
material from the western Indo-Pacific, it is best to postpone taxo- 
nomic recognition of these differences until more extensive populations 
from different parts of the range of Z. trisetacea can be compared. 
Although Zysmata galapagensis Schmitt is very similar to L. 
trisetacea, re-examination of the type series of that species has shown 
that the two are distinct species, as noted by Schmitt in 1939. 
DistriputTion: Red Sea to the Hawaiian Islands and Clipperton 
Island. 
Family Processidae 
Processa hawaiensis (Dana) 
Nika hawaiensis Dana, 1852, p. 538; 1855, pl. 33, fig. 7. 
Processa paucirostris Edmondson, 1930, p. 3, fig. 1; 1946, p. 248, fig. 148b. 
MateERIAL: Poison; October 20, 1956; W. Baldwin; 4 males, 2 
females (1 ovigerous).—Kast end, coral reef; August 15, 1958; Sta. 
W58-289; Reese, Baldwin, and Wintersteen; 4 ovigerous females. 
MEASUREMENTS: Carapace lengths of males, 1.7—2.3 mm.; of female 
without eggs, 1.7 mm.; of ovigerous females, 3.1-4.7 mm. 
Remarks: Processa paucirostris was proposed by Edmondson (1930) 
for a specimen that corresponded with Dana’s description of Nika 
hawaiensis in most particulars. The only important distinguishing 
