34 University of California Publications in Zoology  [Vou. 23 
Hymenodora frontalis Rathbun 
Hymenodora frontalis Rathbun, Proc. U. S. Nat. Mus., 24, 904, 1902; 
H. A. E., 10, 28, 1904. 
Fig. 20. Hymenodora frontalis, 9, X about 2 (from Rathbun, U. 8. N. M.). 
Characters.—Surface covered with very fine wrinkles or rugose lines. Carapace 
and rostrum more than half as long as abdomen; median carina advanced in a 
rostrum which is unusually long for the genus, being from two-fifths to one-half 
as long as the remainder of the carapace and reaching the end or a little beyond 
the end of antennular peduncle. Rostrum a slender, sharp-pointed spine, distal 
half slightly curved upward, basal half armed above with three to six spines, two 
or three of which are beyond the line of the orbit. Abdomen devoid of a median 
carina or median spines; sixth segment two and a half times as long as fifth, and 
between three-fourths and four-fifths as long as telson. 
Dimensions.—Type, male: length of carapace and rostrum 19 mm.; of rostrum 
6.5 mm.; of abdomen 32.5 mm. 
Type Locality—West of Unalaska, 322 fathoms (‘‘ Albatross’’ station 38327). 
Distribution—From Bering Sea to off San Clemente Island, California, and 
Kamchatka; 322 to 1771 fathoms. 
Remarks.—The unusually long rostrum distinguishes this from other species 
of Hymenodora (Rathbun). 
Family PALAEMONIDAE 
Rostrum well developed, laterally compressed, and armed with teeth. Anten- 
nules with three flagella, owing to cleavage of one almost or quite to the base. 
Mandibles with incisor process, and with or without palp of three segments. First 
pair of legs chelate and shorter than second. Second pair equal and chelate, with 
segmented carpus, chelae generally larger than in first pair. 
Or i Ne ee ee 
