DECAPODS BY 
D’. First and second abdominal segments laterally acute. Ros- 
tramp dee pris, xe . . lamellicornis. 
C’. First to third abdominal segments laterally rounded, not acute. 
D. Two supraorbital spines. 
E. Rostrum longer than the remainder of the carapace and 
with a long slender tip . . . . bispinosa. 
E’. Rostrum shorter than the remainder of the carapace. 
F. Rostrum not reaching end of antennular peduncle 
truncata, 
F’. Rostrum reaching beyond end of antennular peduncle. 
G. Antennular scale not reaching middle of second seg- 
ment of peduncle. 
H. Dorsal spines all in front of middle of carapace 
Sica. 
H’. Dorsal spines continued posterior to middle of 
carapace ..% : .  snyderi. 
G’, Antennular scale reaching beyond middle of second 
segment of peduncle. 
H. Dorsal spines not reaching to posterior third of 
carapace. 
J. Upper limb of rostrum gradually diminishing in 
width from the orbit to the tip . . phippsit. 
J’. Upper limb of rostrum arcuate, widest in the 
middle. 
K. Rostrum extending only to end of antennular 
peduncle, deep, usually bifid at tip ochotensis. 
K’. Rostrum extending nearly to end of antennal 
scale, less deep, tip acute . . . . dallt. 
H’. Dorsal spines continued to posterior third of cara- 
pace. 
J. Midrib of rostrum terminating in a spine which 
projects well beyond lower limb of rostrum. 
K. Eyes large, pyriform. Spine of antennal scale 
extending beyond lamellar portion 
hivjeborgit, 
K’. Eyes of moderate size, subcylindrical. Spine 
of antennal scale not reaching beyond lam- 
ellar portion <.. a. « . 6. murdochi. 
J’. Midrib of rostrum terminating in a spine which 
does not project beyond lower limb of rostrum. 
K. Upper margin of carapace and rostrum in 9 
convex. Third abdominal segment in ¢@ in 
profile not projecting behind fourth segment 
arcuata. 
K’. Upper margin of carapace and of rostrum in 9 
separated by a depression. Third abdominal 
segment in ¢ in profile projecting in a horn- 
like process behind fourth segment . spina. 
D’. One supraorbital spine. 
