P E R N A 



Plate II. 



Species G. (Mus. Cuming.) 



Pekna QUADKANGULARis. Pern, testa, sub^uadrata, rude 

 anyulatd, poHice concavo-impressd, versus cardinem 

 lavigatd, deinde obscure ieime concentrice laminatd ; 

 purpitreo-nigrescente. 



The sauARE Perna. Shell somewhat square, rudely 

 angled, posteriorly concavely impressed, smooth to- 

 wards the hinge, then obseurely, thinly, concentri- 

 cally laminated ; purple-black. 



Uab. -^—'i 



A dark-purple species, of marked quadrangular growth, 

 conspicuously concavely impressed beneath the area of the 

 bvssus. 



Species 7. (Mus. Cuming.) 



Peena lingUjEFORMIS. Fern, testa hngitudinaU, versus 

 cardinem irregulariter concentrice laminatd, deinde 

 lavi ; sordide alba. 



The tongce-shaped Perna. Shell longitudinal, irre- 

 gularly concentrically laminated towards the hinge, 

 then smooth ; dead white. 



Hab. Society Islands. 



Of a longitudinal flexuous tongue-shajie and dead white 



hue. 



Species 8. (Mus. Cuming.) 



Perna ephippiu.m. Pern, testa subtrigono-orbiculari, 

 plana, compresse laminatd, laminis fere obsoletis, la- 

 tere antico anrtformi, concaviusculo ; aneo-rufescente. 



The saddle Perna. Shell somewhat triangularly orbi- 

 cular, flat, compressly laminated, laminse almost ob- 

 solete, anterior side ear-shaped, rather concave ; cop- 

 pery-red. 



Ostrea ephippium, Linufeus, Syst. Nat. p. 1149. 



Perna ephippium, Lamarck. 

 Hab. Honduras. 



This species, which appears to be the old type of the 

 genus, is characterized by its flat, coppery-red aspect, the 

 laminae being compressed or caked together so as to be 

 almost obsolete. The anterior side of the shell is, more- 

 over, of a peculiar concave ear-shape. 



Species 9. (Mus. Cuming.) 



Pekna laticostata. Pern, testa longitudinali, f ex ttosd, 

 tri-quadricostatd et conspicue concentrice laminatd, 

 deinde lavi ; sordide alba, purpureo-nigrescente versus 

 extremitatem. tinctd. 



The broad-ribbed Perna. Shell longitudinal, flexu- 

 ous, three- or four-ribbed and conspicuously concen- 

 trically laminated, then smooth ; dead white, tinged 

 towards the extremity with purple-black. 



Hah. ? 



Of a somewhat squarer longitudinally flexuous form than 



the preceding species, rudely rayed with three or four 



broad ribs. 



Species 10. (Mus. Cuming.) 

 Perna vitrea. Pern, testa subquadraio-orbiculari, tenui, 



laevigata, vix laminatd ; nitente-castaned. 

 The glassy Perna. Shell somewhat squarely orbicular, 



thin, smooth, scarcely laminated ; shining-chestnut. 

 Hab. Red Sea. 



Unlike most species of the genus, this is of compara- 

 tively thin substance, and of a shining, dark chestimt-red 

 colour. 



March, 1858. 



