64 
smoothly rounded, without trace of orbito- 
rostral grooves. Orbital teeth short and nar- 
row, reaching 0.7 length of rostrum. 
Second antennular article 1.3 times as long 
as visible portion of first, 1.5 times as long as 
third, twice as long as broad. Stylocerite 
reaching end of first antennular article. 
Lateral spine of basicerite strong, longer 
than rostrum, extending over 0.7 of length of 
first antennular article. Lateral margin of sca- 
phocerite almost straight, tip of lateral spine 
reaching end of antennular peduncle; squa- 
mous portion only 0.05 shorter than spine. 
Carpocerite considerably longer than anten- 
nular peduncle. 
Large chela only moderately heavy, 2.8 
times as long as broad, compressed and with 
distal sculpturing reduced. [For terminology 
of crests and grooves see Fig. lie.] Superior 
crest low, rounded, terminating as relatively 
small acute tooth above dactylar articulation. 
Transverse groove lacking. Superior groove 
shallow and broad. Plaque crest low, rounded, 
but merging with superior margin of palm. 
Palmar groove rounded, narrower than su- 
perior groove. Inferior ridge slight, rounded, 
distally ending as rounded protuberance be- 
low dactylar articulation. Inferior depression 
slight, shoulder low, gradual, and rounded. 
Dactylus similar to that of C. albatrossae Ban- 
ner, with proximal portion narrow and crested, 
distal portion expanded and bulbous. Carpus 
of usual form. Merus equal in length to height 
of palm, 2.7 times as long as breadth of outer 
face, 1.6 times as long as maximum breadth; 
superior margin rounded, unarmed; superior 
distal angle slightly projecting but rounded; 
inferior internal margin with 8 small spines 
and large terminal tooth. Ischium with 2 
spines on superior margin, 5 on inferior 
margin. 
Small cheliped lost. 
Carpal articles of second legs with ratio 
10 : 6 : 4 : 4 : 6. 
Third legs with ischium 0.4 length of me- 
rus, armed with strong spine. Merus 7 times 
as long as broad, unarmed. Carpus 0.6 as long 
PACIFIC SCIENCE, Vol. VII, January, 1953 
as merus, with acute distal projection of su- 
perior margin. Propodus 0.8 as long as merus, 
with 8 inferior and distal spines. Dactylus 0.25 
as long as merus, curved, acute, with 2 su- 
perior serrations, no trace of inferior teeth. 
DISCUSSION: This single specimen came 
from the same dredge haul that produced the 
paratypes of C. albatrossae Banner and super- 
ficially is very similar to them. The basis for 
separation of the species from the other spe- 
cies of the C. hailstonei complex is given in 
Table 2. Probably the most valid and least 
variable characteristics that will serve for the 
identification of this species are the nature of 
the anterior region of the carapace, the ros- 
trum being much shorter and broader than 
that of the other species, and the lack of the 
transverse groove on the large chela. 
Unfortunately, with only one specimen 
available, it cannot be determined whether 
this specimen represents a heretofore uncol- 
lected species or merely an aberrant individ- 
ual, probably of C. albatrossae. Minor genetic 
mutations could account for the differences 
between this and the typical C. albatrossae. 
The fact that the specimen was collected with 
a series of specimens of C. albatrossae would 
incline one toward that belief, but of course 
in a half-hour dredge haul there is no reason 
to suppose that all the specimens came from 
exactly the same habitat. However, the char- 
acteristics mentioned above and some of the 
more minor characteristics, such as the thick- 
ness of the second antennular article, appear 
to be rather constant within a species of this 
group. For these reasons it was decided to 
designate this specimen a species. 
The species is named in honor of Dr. Leon- 
ard D. Tuthill, Department of Zoology and 
Entomology, University of Hawaii. 
Crangon oahuensis sp. nov. 
Fig. 20 a-m 
TYPE SPECIMEN: A male 27 mm. long col- 
lected from coral in water about 20 feet deep 
off Waikiki Reef, Oahu (U.S.N.M. 93455). 
