20 University of California Publications in Zoology [Vol. 23 



Characters. — Eostrum nearly oblong-triangular, with a distinct upward trend, 

 tip acute. Anterior margin of carapace below the rostrum strongly convex and 

 protruding; supraocular and hepatic spines well developed; gastro-hepatic groove 

 distinct. Corneae large, broader than deep, scarcely as long as broad. First joint 

 of antennular peduncle considerably longer than the third, outer margin as long 

 as the same margin of the two distal joints together; second joint rather slender 

 and scarcely longer than the slender third joint. Antennal scale moderately broad 

 at the end, with spine projecting beyond the terminal margin. Third maxillipeds 

 scarcely longer than the third legs. Sixth segment of abdomen twice as long as 

 deep; about as long as, or slightly longer than fourth and fifth together. 



Dimensions. — Type : length 54 mm. ; of largest specimen measured by Miss 

 Rathbun 52 mm.; average about 40 mm. 



Type Locality.— OS. Japan, 345 fathoms ("Challenger" station 232, lat. 35° 

 11' N, long. 139° 28' E). 



Distribution. — Also taken by the "Albatross" from off Destruction Island, 

 Washington, to the Gulf of California, northwest of Tiburon Island, 145 to 2228 

 fathoms. The depth for one station (4468) in Monterey Bay is recorded as 

 51-309-32 fathoms. 



Sergestes sp. indet. 



Sergestes sp. indet., Rathbun, H. A. E., 10, 146, 1904. 



"A single mutilated female Sergestes, without maxillipeds or trunk-legs, was 

 dredged by the 'Albatross' in 417 fathoms off San Diego, California, station 2928. 

 It resembles S. mollis Smith [Rept. U. S. Commissioner Fisheries for 1882, pp. 

 419-421]. Body stout; length about 38 mm. The rostrum and anterior outline 

 are as in that species. There is a minute hepatic spine. A strong ridge runs 

 from the anterior margin at the outer edge of the eye-stalk backward to the 

 posterior margin; the front part of the ridge is higher up than in S. mollis; at its 

 middle the ridge gives off a weaker branch directed obliquely downward and 

 backward, and then backward to the posterior margin. Gastro-cardiae groove 

 deep; cervical groove present. Eyes a little shorter than in S. mollis, reaching 

 % the length of the first antennular segment ; cornea brown. Antennular peduncle 

 rather stout, first joint the longest, 1% times the second joint; second and third 

 subequal; notch in outer side of first segment very slight. Antennal scales broken 

 off. Abdomen as in S. mollis. Telson broken off. No hairs visible on outer 

 margin of outer uropod. " (Rathbun.) 



Family Peneidae 



Rostrum usually well developed, sometimes short and elevated, laterally com- 

 pressed, often toothed. Antennules with two flagella; basal joint of peduncle 

 dorsally concave for the eye, and strengthened at the base, on outer side, by a 

 spine-like scale. Mandibles with incisor process, and palp of one or two segments. 

 First three pairs of legs similar, chelate, and slender, increasing in length from 

 before backward; remaining two pairs well developed, simple. 



Key to the California Genera of the Peneidae 



I. Rostrum toothed above and below. Inner border of first segment of antennular 



peduncle with a twisted setose scale. (Not known north of San Francisco 



Bay.) 



Peneus, p. 21. 



