286 



MARINE INVERTEBRATES 



one inch long, with prominent spines on the sides of the carapace, which 

 narrows in front into a long beak ending in two spines. It is red and 

 green above, red beneath. (Plate LXIII.) 



GENUS Sternorhynchus 



S. Sagittarius. This is one of the most delicately formed of the spider- 

 crabs. The body has narrow longitudinal stripes of light and dark color. 

 It lives offshore from Cape Hatteras southward. 



GENUS Epialtus 



E. productus, the kelp-crab. This crab inhabits the coasts of Cali- 

 fornia and Oregon, and is found among seaweeds on rocks just below 

 low- water mark. The carapace is smooth, is quadrate in form, is about 

 two inches long and broad, has two spines on each side, and has a promi- 

 nent denticulated rostrum. This is the most common spider-crab of the 

 Pacific (California) coast. It is olive-green, thus simulating in color the 

 kelp among which it lives. (See page 285. ) 



GENUS Pitho 



P. acwleata. The carapace has six spines on each side, the middle 

 two being sometimes partly united ; the general outline is pentagonal ; 

 the length about one inch. Quite common on the Florida coast. 

 (Plate LXIII.) 



GENUS Lambrus 



L. pourtalesii u 



the long-armed 

 spider-crab. The 

 carapace is broader 

 than it is long and 

 has three elevations 

 all covered with 

 spines. The general 

 surface is pitted and 

 granulated ; the ros- 

 trum points down- 

 ward ; the chelipeds 

 are very long, the 

 margins armed with 

 spines; the breadth 

 of the carapace is 

 about one and a half 



inches; and the length of the chelipeds is about three and a half inches. 



Its range is from Cape Cod to Florida, and it lives among the rocks, 



(Plate LXIV.) 



Lambnus puurtalesii. 



