70 INVERTEBRATA OF MASSACHUSETTS. 



t.38, f. 399. DESHAYES; Encyc. Mith., Vers., ii. 379. LAM.; An. sans Vert., 



vi. 225. 



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

 Venus spuria, DILLWYN ; Catal., 194. GMELIN ; Syst., 3284. 

 Pectunculus subfusous, LISTER : Conch., I. 293, f. 129. 



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

 hinge margin straight ; beaks 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 1| inch, height the same, breadth 

 T V 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 white, orbicular, lenticular, sculptured with grooves bent 

 obliquely downwards at both sides ; lateral teeth obsolete ; margin 

 dentated. 



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



Tellina divaricata, LIN.; Syst. Nat., 1120. GMELIN'; Syst., iv. 3241. No. 74. 



BONANNI; Recr., iii. f. 349. SCHROET.; Einl. in Conch., ii. 663. PETIV. ; 



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. ; Encyc. Meth., pi. 285, f. 



4, a, b. PQLI; Test., 1. pi. 15, f. 25. DILLWYN ; Catal, i. 102. No. 7. TUR- 



TON ; Conch. Diet., 178. 



Cardium arcuatum, MONTAGU ; Test. Brit., 85, pi. 3, f. 2. 

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

 Luclna divaricata, LAM. ; An. sans Vert., vi. 226. Jinn, du Mus., vii. 239. 



DESHAYES; Encyc. M6th., Vtrs, ii. 376, pi. 285, f. 4. BLAINV.; Malacol. pi. 



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

 Strigilla divaricata, TURTON ; Brit. Biv., 119. 



