DECAPODS 35 



Concepcion Bay, Lower California, and at stations 2824 and 2825 in the 

 Gulf of California, 7 and 8 fathoms. 



They agree with Dr. Holmes's description, except that the fingers of 

 the second pair of feet are only a little over half as long as the palm and 

 the postero-lateral angle of the sixth abdominal segment is subacute. 



Family PANDALIDJZ. 

 Genus Pandalus Leach. 



KEY TO THE SPECIES OF PANDALUS. 



A. Third segment of abdomen in part compressed and carinated, the 

 carina forming a more or less well defined lobe or spine in front 

 of the posterior margin. 

 B. Third and fourth segments of abdomen armed with a median spine 



on posterior margin borealis. 



B'. Third and fourth segments of abdomen without median spine on 



posterior margin. 



C. Rostrum unarmed on distal half of superior margin . goniurus. 

 C'. Rostrum with spines on distal half of superior margin . jordani, 

 A'. Third segment of abdomen not compressed and carinated, and with- 

 out a median lobe or spine in front of posterior margin. 

 B. Dorsal spines not reaching behind middle of carapace. 



C. Sixth abdominal segment more than twice as long as wide. 

 D. Carapace and abdomen covered with short transverse rugose 



lines leptocerus. 



D'. Carapace and abdomen smooth .... montagui tridens. 

 C'. Sixth abdominal segment less than twice as long as 



wide platyceros. 



B'. Dorsal spines extending behind middle of carapace. 



C. Dorsal spines more than 15 (17-21) hypsinotus. 



C'. Dorsal spines less than 1 5. 



D. Rostrum one and a half or more than one and a half times as 



long as carapace gurneyi. 



D'. Rostrum less than one and a half times as long as carapace. 

 E. Antennal scale very narrow, the terminal half of the blade 

 narrower than the adjacent thickened portion stenolepis. 

 E'. Antennal scale of moderate width, the terminal half of the 

 blade not narrower than the adjacent thickened por- 

 tion dance. 



PANDALUS BOREALIS Kroyer. 



Pandalus borealis KROYER, Naturh. Tidsskrift, II, 254, 1838; (2)1, 461, 

 1845 ; in Gaimard's Voyage en Scandinavie, en Laponie, etc., pi. vi, fig. 2. 

 STIMPSON, Jour.Boston Soc. Nat. Hist, vi, 501 [6i],i857; Ann.Lyc.Nat. 

 Hist. N. Y., x, 128, 1871. SMITH, Trans. Conn. Acad. Arts Sci., v, 86, 

 1879. BIRULA, Ann. Mus. Zool. Acad. Imper, Sci. St. Petersbourg, 

 1897, p. 420 [16] ; 1899, pp. 22 [3], 28 [9]. 



