46 University of California Publioations in Zoology [Vol. 23 



would have conditions of temperature and salinity favoring an exten- 

 sion of the range of Pandalus danae, but at this period as well as 

 during the remainder of the year it is no doubt the absence of suf- 

 ficient areas of favorable bottom elsewhere in the bay, together with 

 the decrease in depth, that exercises the potent influence in restricting 

 this species to the region of its observed distribution. 



It is impossible to explain why no specimens of Pandalus danae 

 were taken outside, for Dr. Rathbun says (1884, p. 821) : 



This Prawn lias been much more abundant in the San Francisco markets during 

 the past two years than formerly, and the reason assigned is that the fishermen, 

 driven out of San Francisco Bay by the constantly diminishing supply of fish 

 there, have been forced to resort to the open sea between the Farallone Islands 

 and Point Reyes, where the Prawns live in large numbers. 



Pandalus gurneyi Stimpson 

 Plate 13, figure 1 



Pandalus gurneyi Stimpson, Ann. Lye. Nat. Hist., 1ST. Y., 10, 128, 1871 ; 

 Eathbun, H. A. E., 10, 50, pi. 2, fig. 6, 1904. 



Characters. — Very near P. danae. Rostrum one and one-half to one and two- 

 thirds longer than the carapace. Median dorsal spines eight or nine, all movable, 

 rather distant ; ventral spines nine or ten, immovable. Antennal seale as long 

 as carapace. Right leg of second pair extends to tip of acicle, carpal segments 

 seventeen ; left leg one-third longer than right, carpal segments about forty-five. 

 Sixth segment of abdomen one and one-half times as long as wide. 



Dimensions.— Ovigerous female: length 77.5 mm., length of carapace and 

 rostrum 38.5 'mm., of rostrum 25 mm. (Ratlibun). 



Type Locality. — Monterey, California. 



Distribution. — Monterey to San Pedro, and Santa Catalina Island, California, 

 9 to 55 fathoms. 



Genus Pandalopsis Bate 



Antennules twice the length of the carapace. Merus of third maxillipeds with 

 inner margin longitudinally developed into a broad laminate expansion fringed 

 with long hairs. Ischium of first pair of thoracic legs also with large laminate 

 expansion, the lower margin of which is fringed with a row of hairs on the 

 inner side. 



Pandalopsis ampla Bate 



Plate 14, figure 2 



Pandalopsis amplus Bate, ' ' Challenger ' ' Rept., Zool., 24, Macrura, p. 671, 

 pi. 175, fig. 3, 1888. 



Pandalopsis ampla Faxon, Mem. Mus. Comp. Zool., 18, 155, 1895; Rath- 

 bun, H. A. E., 10, 51, 1904. 



