SMITH : MARINE SHELLS FROM NEW ZEALAND. 23 



4. Macoma Suteri, n.sp. Fig. VI. 



Testa albida, paulo ingequilateralis, antice late rotundata, postice 

 niulto angustior, ad extremitatem. acute arcuata, ad ventrem late 

 curvata ; margo dorsi anticus leviter obliquus, posticus magis obliquus ; 

 umbones pi'oniiiientes, acuti ; valvse tenues, eoncentrice tenuiter 

 striatae, mediocriter convexae ; dentes duo cardinales divergentes in . 

 valva dextra, in sinistra unicus bifidus ; pagina interna nitida, 

 radiatim substriata; cicatrix autica parva, elongata, postica major, 

 rotundata ; sinus pallii profundus, rotundatus ; ligamentum externum 

 elongatum, parte antica prominente ; internum (resilium) parvum, 

 obliquum, postice declive. Long. 15, alt. 12, diam. 5-5 mm. 



Mob. — Lyttelton Harbour, in 2-4 fathoms (Suter). 



The presence of an internal ligament or resilium distinguishes this 

 species from the typical form of Macoma, which is furnished with an 

 external ligament only. The presence of an internal ligament in the 

 British Tellina donacina and some other forms of Tellinidse has already 

 been pointed out by the writer in the Eeport on the "Challenger" 

 Lamellibranchiata, p. 106; but what systematic value this character 

 may possess has yet to be determined when the entire family is 

 critically studied. 



5. Mactra ordinaria, n.sp. Fig. VII. 



Testa triangulariter ovata, paulo insequilateralis, alba, periostraco 

 tenui griseo induta, eoncentrice tenuiter striata, supra dorsi aream 

 utrinque sulcata ; margo dorsi posticus arcuatus, declivis, anticus seque 

 obliquus sed rectior, margo ventris minime curvatus ; valvse tenues, 

 areis dorsi utrinque plus minus circumscriptis ; pagina interna alba ; 

 cicatrix anterior parva, pyriformis, posterior major, rotundata ; sinus 

 pallii latus, baud profundus; cardo normalis. Long. 13, alt. 9'5, 

 diam. 5-5 mm. 



Hob. — Lyttelton Harbour, in 4 fathoms. 



This species probably attains larger dimensions than those here 

 given. It is of ordinary appearance, but somewhat straight along 

 the ventral margin and rather pointed at both ends. 



6. Saxicava arctica (Linn.). 



Hab. — Macquarie Island (A. Hamilton). 



Two specimens about 7 mm. in length appear undistinguishable 

 from the cosmopolitan S. arctica (Linn.). In the Eeport upon the 

 Lamellibranchiata of the "Challenger" Expedition, p. 78, a list is 

 given of the numerous localities cited for this polymorphous species. 

 It occurs both in Patagonia and Kerguelen Island. 



7. Las^a miliaris (Phil.), var. 



Kellia miliaris, Philippi : Wiegmann's Archiv fiir ]S"aturges., 1845, 

 p. 51. 



Sab. — Dunedin Harbour and Macquarie Island (A. Hamilton). 



