DECAPODS 7 



species which follow the coast-line. The occurrence of some 

 abyssal forms, as Hymenodora glacialis and H. frontalis, in the 

 deep pocket (1569 fathoms) east of Prince of Wales Island is 

 worthy of note. 



The following is a list of the genera occurring below the 500- 

 fathom line. Those whose range extends below 1000 fathoms 

 are printed in italics : 



Pasiphaa Pagurus (2 species) 



Parapasiphae Parapagurus 



Acanthephyra Pristopus 



Hymenodora Leptolithodes 



Pandalopsis (i species) Lithodes 



Spirontocaris (5 species) Munida 



Crangon (3 species) Munidopsis 



Sergestes Chorilia 



Benthesicymus Chioncecetes 



Gennadas Hyas 



Calastacus 



Dr. Dall * divides his Oregonian fauna, which stretches from the 

 end of the Aleutian chain to Point Conception, California, into 

 three subfaunal areas, with divisions at Yakutat Bay or Mount St. 

 Elias, Alaska, and at Cape Mendocino, California. 



Professor Nutting, 2 on the other hand, reasoning from his study 

 of the Hydroids, emphasizes the effectiveness of Puget Sound as 

 a faunal barrier and the continuity of the area between that point 

 and the end of the Aleutian chain. 3 



It is highly probable that future research will make it possible 

 to subdivide the coast into several small areas. The accompany- 

 ing table shows the intricate overlapping of species. 



i The Fur Seals and Fur-Seal Islands of the North Pacific Ocean, Pt. in, 539-546, 

 1899. 



2 Proc. Wash. Acad. Sci., in, 161, 1901. 



3 Professor Nutting had not consulted Dr. Dall's report above cited, in which state- 

 ments made twenty-three years earlier are considerably modified. 



