CORBULA.— Plate IV. 



Species 30. (Mus. Cuming.) 



Corbula adusta. Corb. testa suboblique trigond, laevi- 

 gata, tumidiusculd, postice rotundatd, antice leviter 

 angulato-acuminatd ; rubido-fuscd , epidermide corned 

 indutd ; umbonibus erosis. 



The burnt Corbula. Shell somewhat obliquely tri- 

 angular, smooth, rather swollen, rounded poste- 

 riorly, slightly angulately acuminated anteriorly ; 

 reddish brown, covered with a horny epidermis ; 

 umbones eroded. 



Hinds, Pro. Zool. Soc., 1844. 



Hab. New Zealand. 



Differs from the preceding species in being rather 



stouter, and less anteriorly acuminated. 



Species 31. (Fig. a, Mus. Cuming, Fig. b, Mus. Saul.) 

 Corbula nimbosa. Corb. testd trigono-ovatd, Iccvigntd 

 postice rotundatd, antice subangulato-productd ; al 

 bidd, epidermide pallide olivaced, lineis nigricantibus 

 capillaribus undatis prope umbones radiatim pietii 

 umbonibus erosis, subcenlralibus. 

 The rainy Corbula. Shell triangularly ovate, smooth 

 rounded posteriorly , rather angularly produced an 

 teriorly ; whitish, epidermis pale olive, radiately 

 painted near the umbones with zigzag blackish 

 hair-like lines ; umbones eroded, nearly central. 

 Potamomya nimbosa, Sowerby, Conch. Manual, 

 f.498 and 499. 

 Nab. The tributary streams of the Rio de la Plata (found 

 in the mud) ; Cuming. 

 This species may be easily distinguished by the deli- 

 cate zigzag hair-lines which ornament the valves around 

 the umbones. 



Species 32. (Mus. Cuming.) 



Corbula ochreata. Corb. testa elongatd, latere postico 

 abbreviato, rotundato, antico angulato -acuminata , 

 laevigata, umbones versus leviter corrugatd ; albidd, 

 epidermide corned pallidissim'e olivaced indutd ; um- 

 bonibus erosis. 



The pale Corbula. Shell elongated, posterior side 

 abbreviated, rounded, anterior angulately acumi- 

 nated ; smooth, slightly wrinkled towards the um- 

 bones ; whitish, covered with a very pale olive horny 

 epidermis ; umbones eroded. 

 Potamomya ochreata, Hinds, Pro. Zool. Soc, 1843. 



Hab. Brazil (found in fresh-water streams). 



There is no indication in this species of the black 



hair-like lines which so neatly adorn the preceding. 



Species 33. (Mus. Cuming.) 



Corbula cuneata. Corb. testd trigono-ovatd, sotidd, 

 subicqiiivalvi, latere postico rotundato, antico angulato; 

 longitudiinditcr sulcata, liris intermediis prominen- 

 libus ; albidd, purpurascente pallide tinctd ; umbo- 

 nibus subdepressis , postice albiradiatis . 



The wedge-shaped Corbula. Shell triangularly ovate, 

 solid, nearly equivalve ; posterior side rounded, an- 

 terior angulated ; longitudinally grooved, interme- 

 diate ridges prominent ; whitish, palely tinged with 

 purple ; umbones rather depressed, rayed with 

 white on the posterior side. 



Hinds, Pro. Zool. Soc, 1843. 



Hab. Catbalonga, Philippine Islands (found in soft mud 



at the depth of ten fathoms and upwards), Cuming ; 



and Lagulhas Bank, Cape of Good Hope (at the 



depth of seventy fathoms) ; Hinds. 



This species partakes of the characters of the Corbulee 



tunicata and crassa. 



