30 
PACIFIC SCIENCE, VoL VII, January, 1953 
with strong tufts of setae. Carpus as large as 
propodus, expanded, on some sides almost 
forming collar for base of palm; article twice 
as broad as long. Merus without spines, twice 
as long as broad, and equal in length to chela. 
Second legs very heavy and short, 2.3 mm, 
long, merus 0.16 mm. in maximum width. 
Ischium 0.48 mm. long, 0.13 mm. broad. 
Merus 0.71 mm. long, 0.16 mm. broad. Only 
4 secondary carpal articles with ratio 10 : 3.6 
: 2.8 : 7.6; fourth secondary article 1.5 times 
as long as broad. Chela 0.6 as long as carpus, 
slightly broader than carpus; fingers 0.5 
length of chela. 
Third legs also relatively heavy, 2.1 mm. 
long. Ischium 0.33 mm, long, inermous. Me- 
rus 0.76 mm. long, 0.22 mm. broad, unarmed. 
Carpus 0.29 mm. long, with superior distal 
margin produced as rounded tooth. Propodus 
slightly curved, 0.77 mm. long, 0.14 mm. 
broad, bearing 4 feeble spines on inferior 
margin. Dactylus 0.20 mm. long, 0.07 mm. 
broad at base, biunguiculate, with superior or 
distal claw not as broad at base as inferior, 
about 1.5 times as long as inferior; superior 
claw more acute than inferior. Fourth legs 
similar. 
Fifth legs with "brush” feebly developed, 
consisting of but 3 tufts of 3 bristles each. 
Dactylus with superior unguis thinner than 
on preceding legs, 
Telson 1.2 times as long as broad at base, 
with tip 0.5 as broad as base. Lateral margins 
convex distally; distal margin strongly arcuate 
and bearing 4 plumose setae. Large pair of 
terminal spines approximately 0.5 as long as 
breadth of tip of telson. Dorsal surface slight- 
ly convex, without any trace of usual 2 pairs 
of dorsal spinules. 
DISCUSSION: This species, in spite of the 
four-jointed carpus of the second legs, plainly 
belongs to the genus Synalpheus. The shape 
and development of the anterior region of the 
carapace, including the pterygostomial angle, 
are similar to other species of the genus; ex- 
cept for the second legs, the appendages in 
their development parallel the development 
found in Synalpheus. The important branchial 
formula is the same as that of other members 
of the genus. 
The unique four-jointed carpus will separ- 
ate this species from all other members of the 
genus, however. Other genera of crangonids 
have fewer articles than the usual five, e.g., 
Fterocaris Heller, Ogyris Stimpson, Arete Stimp- 
son, and Alpheopsis Coutiere. Moreover, in 
Alpheopsis there are species with both three and 
five articles to the carpus. However, the other 
characteristics of this species do not fit these 
genera. 
To my knowledge the lack of dorsal spi- 
nules on the telson is a characteristic that is 
unique among the Pacific synalpheids, al- 
though Coutike states (1899: 316) "Quelques 
especes [of the genus Synalpheus] . . . montrent 
une reduction tres grande des epines, ou 
meme leur disparition totale.” 
This species does not fit the subgeneric 
groups created by Coutiere very satisfactorily. 
It apparently belongs to either the Neomeris 
or Paulsoni group. From the former it differs 
in that the two hooks of the third and fourth 
dactyli are subequal; from the latter in that 
the rostrum has no ventral prolongation that 
"embraces the ocellary beak” (Coutiere 1909: 
4) . Should other species with similar develop- 
ment of the carpus be described, they should 
be included with this species in a special 
group; however, the creation of a new group 
does not seem practical for this single species. 
Of the Hawaiian specimens studied, S. re- 
dactocarpus appears to be most closely related 
to S. hiunguiculatus (Stimpson), but it differs 
from this species in the length of the spines of 
the stylocerite and basicerite, in the large and 
small chela, and in the dactyli of the third to 
fifth legs. 
Synalpheus albatrossi CoutiHe 
Fig. 9 a-i 
Synalpheus albatrossi Coutiere, U. S. Natl. Mus., 
Proc. 36: 89, fig. 54a-k, 1909- 
DESCRIPTION: Rostrum acute, narrow, pro- 
jecting to 0.3 of second article of antennular 
