Pacific Shores of North America. 25 



cheirogonus hippocarcinoides. Latreille. 



Cancer adsperso-setosus hippocarcinoides, Steller, MS. (fide Tilesii.) 

 Cancer chciragonus, Tilesius; Mem. de I' Acad. Imp. des Sciences de St. Petersb. 



1815, v. 347, PI. VII. f. 1. 

 Cheiragonus hippocarcinoides, Latreille; Fam. Nat. 1825, p. 270. (fide 



Brandtii.) 

 Platycorystes ambiguns, Brandt ; Bulletin physico-mathem. de VAcad. de St. 



Petersb. 1849, vii. 179. 

 Platycorystes cheiragonus, Brandt ; in Middendorff's Sibirische Reise, ZoOl. i. 85. 

 Cheiragonus hippocarcinoides, Brandt ; in Midd. Sibirische Reise, ZoOl. i. 147. 

 Telmessus serratus, Dana; U. S. Exploring Expedition, Crust, i. 303, PL XVIII. 



f. 8, (uix White.) 



This crab may be distinguished among those of this coast 

 by its scabrous and setose surface, and the large triangular 

 lateral teeth, of which there are four on the antero-lateral 

 and two on the postero-lateral margin. These teeth have 

 serrated margins, and the outer one on each side is much 

 the largest. The inter-antennary front, which is separated 

 from the praeorbital tooth on either side by a broad sinus, 

 has four small equal teeth. Length about two inches. It 

 was found on the coast of Upper California by Dr. Le 

 Conte ; in Puget Sound by the Exploring Expedition ; and 

 at Sitka by Wosnessenski. 



Mus. Acad. Petrop. ; Expl. Exped. ; Phil. Acad. 



cheirogonus isenbeckii. Brandt. 



Platycorystes Isenbeckii, Brandt ; Bulletin physico-mathem. de VAcad. de St. 



Petersb. 1849, vii. 179. 

 Cheiragonus Isenbeckii, Brandt; in Middendorff's Sibirische Reise, ZoOl. i. 147. 



Unalaschka, (Wosnessenski.) 



Mus. Acad. Petrop. 



This very distinct genus, to which so many names have 

 recently been applied, is now known to include at least four 

 species. That found on the west coast of North Amer- 

 ica, which occurs also along the shores of the Aleutian 

 Islands, of Kamtschatka, and the Sea of Ochotsk, is dis- 

 4 



