70 INVERTEBRATA OF MASSACHUSETTS. 



t. 38, f. 399. Deshayes; Encyc. Mdth., Vers., ii. 379. Lam.; An. sans Vert., 



vi. 225. 

 Venus borealis, Donovan; Brit. Shells, iv. pi. 130. 

 Venus spuria, DiLLWYN ; Catal. ,194. Gmelin ; Si/s«, 3284. 

 Pectunculus subfuscus, Lister ; Conch., I. 293, f. 129. 



Shell white, thick, orbicular, regularly but moderately convex ; 

 hinge margin straight ; beak.g small, pointed, slightly prominent, 

 inclining forwards over a small, indented, smooth, lanceolate 

 lunule ; on each side of the hinge runs a shallow furrow, which, 

 terminating in the margin, causes a slight undulation. Surface 

 covered with fine concentric, lamellar ridges, in the intervals of 

 which are often seen minute, radiating lines ; interior chalky- 

 white, except around the margin, where it is polished ; with 

 radiating lines, most apparent near the margin. Hinge straight, 

 without lateral teeth, and with a single cardinal tooth in the left 

 valve, and two small, diverging ones in the right. Anterior mus- 

 cular impression very narrow, and directed obliquely to the 

 centre of the valves. Length li inch, height the same, breadth 

 -^ inch. 



This must be considered a rare shell, and an inhabitant of deep 

 water. A few valves have been picked up on our beaches after 

 severe storms. It is a common shell on the other side of the 

 Atlantic. 



Luci'na divarica'ta. 



Shell while., orbicular ., letiticitlar, sculptured toith grooves bent 

 obliquely downwards at both sides ; lateral teeth obsolete ; margin 

 dentated. 



State Coll., No. 214. Soc. Cab., No. 1792. 



Tellina divaricuta, Lin.; Syst. JVat., 1120. Gmelin ; Syst., iv. 3241. No. 74. 



BoNANNi ; Recr., iii. f. 349. Schroet.; Einl. in Conch., ii. G63. Petit.; 



Gaz., t. 156, f. 26. Klein ; OstracoL, t. 9, f. 28. Favanne ; Conch., pi. 48, f. 



E. Chemn. ; Conch , vi. 134, t. 13, f. 129. Brug. ; Encijc. Mith., pi. 285, f. 



4, a, b. PsLi ; Test., 1. pi. 15, f, 25. Dillwvn ; Catal, i. 102. No. 7. Tur- 



TON ; Conch. Did., 178. 

 Cardiuin arcuiMum, Montagu ; Test. Brit., 85, pi. 3, f. 2. 

 Pectunculus parvus. Lister ; Conch., t. 301, f. 142. 

 Lucina divaricata. Lam. ; An. sans Vert., vi. 226. Ann. du J\his., vii. 239. 



Deshayes; Encyc. M6th., Vers, ii. 376, pi. 285, f. 4. Blainv. ; Malacol. pi. 



72, f. 3, 3 a. Payraudeau ; Catal, 42, No. 69. 

 Stritrilla divaric^ita, Turton ; Brit. Biv., 119. 



