SOUTH AFRICAN MARINE MOLLLTSCA. 215 



lira ad aiiguluni et altera in medio area^ posticje quain aliis 

 majori])iis, snbsquaniatis, liiieis iiicrementi irregularibus 

 sti'iattt, intus alba"; valva sinistra dextra minor; umbones ad 

 apicem nitidi, longe ante medium siti, subterminali ; dens 

 cardinab's unicus in valva sinistra; valva dextra edentula ; 

 cicatrices et linea pallii obscure. 



Long-it. 5'25, alt. 3, diam. 2 mm. 



Hab. — Tongaat, Natal (H. Burnup). 



This species must not be confused with the young of S . 

 arc tic a, from which it can at once be separated by the fine 

 radiating and somewhat wrinkly lira}. The posterior area of the 

 valves is marked off b}' a somewhat squamous ridge forming an 

 angle from the umbones to the hinder extremity of the ventral 

 margin. A second similar squamous lira is situated between 

 the angle and the dorsal line. The surface of the valves is 

 rather irregular, presenting somewhat rough lines of growth, 



Saxicava arenacea n. sp. PI. YITI, fig. 7. 



Testa parva, oblonga, valde inajquilateralis, compressa, 

 tenuis, vix pellucida, antice rotundata, postice latior, oblique 

 arcuatim truncata; valvas aequales, lineis incrementi striata?, 

 undique quasi arenacea^ marginem versus pallide fuscescentes; 

 umbones' parvi, minime prominentes, ad apicem pellucidi, 

 nitentes, rotundati, longe ante medium siti ; dens unicus in 

 utraque valva, in valva dextra sub apicem umbonis, in sinistra 

 ante apicem ; ligamentum parvum ; margo dorsi posticus infra 

 ligamentum incrassatus ; pagina interna nitida; cicatrices 

 indistincta3, anterior posteriore latior; linea pallii incon- 

 spicua, 



Longit. 4-5, alt. 2*5, diam. 1"5 mm. 



Hab, — Durban, Natal (H. Burnup). 



This is not the young- state of Saxicava arctica, being- 

 different in form, and having a dull arenaceous surface. 

 It may, however, attain larger dimensions than the shells 

 described. 



