Venerupis.] PELECYPODA. 999 



Type in the British Museum. 



Hob. North and South Islands, but more common in the North. 

 Chatham Islands. 



3. Venerupis siliqua, Deshaves, 1854. Plate 62, fig. 8. 



Venerupis siliqua, Desh., P.Z.S., 1853 (1854), 5, pi. 18, f. 1 ; Crit. List, 40 ; 

 M.N.Z.M., 152 ; Index, 90. 



Shell rather small, elongate, transverse, somewhat inflated, 

 inequilateral, unequally concentrically striated, yellowish - white. 

 Beaks approximate, situate at the anterior fourth of length, not much 

 raised, tumid, with an obtuse posterior angle, turned forwards. 

 Anterior end short, rounded, the dorsal margin slightly excavated and 

 descending ; posterior end truncated, angled above towards the 

 straight horizontal dorsal margin ; basal margin broadly convex. 

 There is no lunule. Escutcheon long, deep, and narrow, on the left 

 valve only. Sculpture consisting of unequal, concentric, irregular 

 lamellae, larger and higher behind, more or less anastomosing on the 

 sides ; radial striae in the interspaces feebly indicated, crossing the 

 interstitial fine concentric threads. Colour dirty yellowish-white. 

 Interior yellowish - white, the posterior part sometimes purple. 

 Margins smooth. Hinge narrow, 3 cardinals in each valve,, the 

 anterior tooth in the right valve slender, entire, the others strong, 

 grooved ; in the left valve the posterior cardinal tooth a long, 

 slender, and very oblique lamella, the middle tooth strongest, tri- 

 angular, bifid, the anterior tooth fairly strong, entire or slightly 

 grooved. Ligament short and stout. Adductor-scars unequal, the an- 

 terior smaller, ovate, the posterior round. Pallial sinus linguiform, 

 extending to the middle of the valves, narrowly rounded in front. 



Length, 26 mm. ; height, 15 mm. ; diameter, 10 mm. 



Type in the British Museum. 



Hob. New Zealand (Cuming) : Hohoura Bay ; Hauraki Gulf ; 

 Manukau Harbour ; Gisborne. 



SUBORDER 5. CARDIACEA. 



Eulamettibranchia with 2 pallial sutures. Generally with short 

 siphons. The foot cylindrical, more or less elongated, furnished 

 with a byssogenous apparatus. The gills much folded. 



Shell equivalve, with radiating costae, external ligament, and 

 conical cardinal teeth, the lateral laminae short, distant. 



Fam. CARDIIDJE, Gray. 



Animal with the mantle slightly closed ; siphons very short, and 

 surrounded by a single circle of papillae, which are often oculiferous. 

 Foot very long, geniculated. 



Shell-substance cellulo-crystalline, with the external layer more 

 or less tubular ; valves equal, free, gaping slightly behind, the beaks 



