40 Crustacea and Echinodermata of the 



islands, belongs to this division. They live under flat 

 stones, from half-tide to low-water mark, and represent the 

 Porcellance of warmer latitudes. 



dermatueus mandtii. Brandt. 



Dermaturus Mandtii, Brandt ; Melanges Biologiques, i. 57. 



Hob. Island of St. Paul. 

 Mus. Acad. Petrop. 



HAPALOGASTER MERTENSII. Brandt. 

 Hapalogaster Mertensii, Brandt ; Melanges Biologiques, i. 58. 



Hab. Sitka, (Wosnessenski.) 

 Mus. Acad. Petrop. 



Tribe PORCELLANIDEA. 



PORCELLANA edwardsii. De Saussure. 



Porcellana Edwardsii. Da S.vi ssi bub \ Rm.et Mag. de ZoOl. v. 306. PI. XI. f. 3. 



Carapax strigose ; surface of hands scabrous ; anterior 

 margin of carpus in the first pair of feet, and of the third 

 article in the remaining pairs, strongly toothed. 



Hab. Mazatlan, (Verreaux.) 



Mus. Paris. 



PORCELLANA RUPICOLA. Stimpson. 



Plate XJX. f. 2. 



Porcellana rupicola, Stimpson; Proc. Bost. Soc. Nat. llisf. vi. 85. 



Carapax moderately depressed ; front triangular^ consid- 

 erably deflected, with a blunt extremity, and a notch or 

 groove at the base separating it from the orbit. Surface of 

 the feet and anterior half of the carapax scarcely rugose, 

 with granules but slightly prominent. The portion of the 





