158 GENUS MONOLEPIS. [November. 



shorter than the others, hand gibbous above and furnished 

 with a tubercle at the base Avithin; tarsi simple as long as 

 the preceding joint, those of the posterior feet furnished 

 with three, elongated setas at the extremity; ptctoral 

 groove with the margin elevated, interrupted, unequal. 



Length of the thorax one fourth of an inch. 



Of this interesting animal I found several specimens 

 on the eastern shore of Maryland, which had been cast 

 on the beach by the refluent tide. They appeared desir- 

 ous to protect themselves from the dashing of the surf, 

 and the influence of the sun, by burrowing in the sand, 

 in order to wait the return of the tide; but their efforts 

 had no further effect on the compact sand, than to raise a 

 small portion of the surface, which, by the action of the 

 waves was spread over them so as to be distinguishable 

 from the general surface by a small elevation. 



2. jNI, spinitarsiis. Tarsi spinose beneath; tubercle 

 behind the eyes obsolete; hind feet terminated by three 

 setas; rostrum deflected. * 



Inhabits South Carolina, 



Cabinet of the Academy. 



Clijpeus rather prominent between the eyes; rostrum 

 deflected, and adprcssed to the face; tubercle of the 

 side of the body obsolete; tarsi armed beneath with 

 about seven, rigid, acute spines, of which the fifth one is 

 largest, and the sixth one smallest, tip incurved, acute; 

 pectoral groove with the margin simple, equal; hind feet 

 smallest, terminal setai longer than the tarsus, and insert- 

 ed near the tip. 



Length of the thorax rather more than | of an inch. 



This description is drawn from two specimens in the 

 possession of the academy which were found abojit thirty 



