42 University of California Publications in Zoology [Vol. 23 



rounded, and equally produced with the spine. Eight leg of second pair extends 

 about to end of antennal scale; the left leg may be half again as long; the right 

 carpus has nineteen to twenty-two segments, the left fifty-eight to sixty-three 

 segments. Third segment of abdomen compressed and its posterior half carinated, 

 the carina interrupted by a slight lobe at the posterior third of the segment; this 

 lobe is of varying size, at no time strong, and has a tendency to disappear in 

 large specimens, in which it may occur only as a slight unevenness in the curve, 

 seen in profile ; posterior margin well produced backward, rounded, unarmed ; sixth 

 segment of abdomen slender, about three times as long as wide. 



Dimensions. — Type, ovigerous female : length 124.5 mm., length of carapace 

 and rostrum 59.5 mm., of rostrum 38 mm. 



Type Locality. — Off Santa Cruz Island, California, 155 fathoms ("Albatross" 

 station 2949). 



Distribution. — From Unalaska to off San Diego, California, 25 to 199 fathoms. 



Remarks. — Distinguished from P. borealis (north Pacific and Atlantic), which 

 has a similar rostrum, by the reduction of the abdominal lobe or hump and the 

 absence of posterior median spines on third and fourth segments. 



Biological Survey of San Francisco Bay. — Of the seventeen "out- 

 side" stations, Pandalus jordani was taken at seven, D 5785-5791, 

 representing all of those at which the depth exceeded 29 fathoms. At 

 four of the stations from one to eighteen specimens were taken, from 

 each of the other three more than fifty were obtained. With but one 

 exception the bottom was ' ' very fine, green sand. ' ' From exceptional 

 station, D 5791, very little bottom material was brought up other than 

 "refuse and garbage." The ranges for temperature and salinity 

 recorded at the time of making the various hauls were respectively 

 9.3° to 12.2° C and 33.9 to 34.4. Crago alashensis elongata also 

 occurred quite abundantly at each of these stations. 



Pandalus montagui tridens Rathbun 



Plate 13, figure 2 



Pandalus montagui tridens Eathbun, Proc. TJ. S. Nat. Mus., 24, 901, 1902 ; 

 H. A. E., 10, 41, pi. 2, fig. 2, 1904. 



Characters. — Eostrum slender, from one and one-half to one and four-fifths 

 times the length of carapace. Dorsal spines ten to twelve in number, all movable, 

 three to five on the carapace and the remainder on the basal half of the rostrum ; 

 posterior spine just in front of middle of .carapace; inferior spines six or seven, 

 rigid;' distal two-thirds of rostrum ascending, tip trifid. Antennal scale with 

 outer margin slightly arcuate; blade truncate at tip, spine stout, reaching to or 

 beyond the end of blade. Eight leg of second pair with carpus divided into twenty 

 to twenty-eight segments. Left leg of second pair with carpus divided into about 

 seventy-four segments. Sixth segment of abdomen slender, about three times as 

 long as wide. 



