MARINE MOLLUSCA OP THE UNITED STATES. 163 



Genus ASTAETE, Sowerby. 

 Min. Conch., t. 137. 1816. 



Animal with mantle open; margins plain or slightly fringed; 

 siphon al orifices simple ; foot moderate, tongue-shaped ; lips large, 

 palpi lanceolate ; gills nearly equal, united behind, and attached 

 to the siphonal band. 



The genus is Arctic in distribution ; a few species found in warm 

 climates are scarcely typical. 



1. A. BOREALIS, Chemnitz. Fig. 407. 



Conch. Cab., vii. t. 39, f. 412. 1784. 



Astarte semisulcata, Leach, Ann. Phil., xiv. f. 204. Gould, Invert. Mass., 



edit. ii. 121. 1870. 

 Astarte lactea, Gould, Invert. Mass., edit. i. 80. 1841. 



Shell orbicular elliptical, compressed, with remote, obtuse, 

 rounded ridges; beaks nearly central; epidermis yellowish-brown, 

 an obsolete lateral tooth in each valve ; margin plain. 



Length 27.5, height 25 mill. 



New England to Arctic Ocean. 



2. A. CASTANEA, Say. Figs. 408, 409, 410. 



Journ. Philad. Acad., ii. 273. 1822. 



Shell thick and heav}^, subtrigonal, with prominent and nearly 

 central beaks, much more elevated than usual in the genus. Sur- 

 face with minute wrinkles and larger concentric waves, and faint 

 traces of radiating lines. Anterior area very deeply excavated, 

 short, broad, and smooth ; posterior slope almost straight, with a 

 long narrow lanceolate depression. Margin internally crenulated. 

 Epidermis chestnut-brown. 



Length and height 1 inch. 



New England to New Jeney. 



The foot of the animal is a bright vermilion color. The high 

 beaks curved forwards, giving the shell a somewhat kidney-form 

 appearance, will distinguish this species from all others. It is the 

 only species occurring as far south as southern coast of New Jer- 

 sey, where it is not uncommon. 



3. A. COMPRESSA, Montagu. Fig. 411. 



( Venus.) Test. Brit. Suppl. 43, t. 26, f. 1. 1803. 

 Astarte striata, Gray. Append. Beechey's Voy., t. 44, f. 9. 

 Astarte Banksti, Leach, Append. Ross' Voy. 1819. 



Shell small, ovate-triangular, elevated, beaks prominent, acute ; 



