125 



A delicate greenish species, in •which the epidermis lies on the 

 posterior area in rows of fine bristles. 



Arca fasciata. Arca testd oblongd, tenui, compressd, laterihus 

 rotundatis, superne attenuatis ; albidd./asciis cinereo-purjmrascen- 

 tibus indistinctis concentrice tinctd ; epidermide tenui, postice se- 

 tosd, induta ; radiatim striatd, striis elevatis, irregularibus. striis 

 transversis subtilissimis fiinbriato-decussatis ; Ugamenti ared an- 

 gustd, profunde declivi ; intus purpurascente. 



Conch. Icon. Arca, pi. 15. f. 99. 



Hab. ? 



This is a remarkably flattened shell, banded and stained with red- 

 dish and ashy purple botli inside and outside. 



Arca lima. Arca testd elongato-ovatd, lateribus superne angulatis, 

 antico infra rotundato, postico angiilato-rotiindato, subextenso ; 

 fuscescente, fusco tinctd, postice fusco maculatd, epidermide tenui 

 subtilissinie setosd indutd, radiatim liratd, liris angustis, numero- 

 sis, confertis, granosis, perpaucis medianis dupUcatis ; lateraliter 

 costatd, costis rudibus, sttbdistantibus, crenato-nodosis ; Ugamenti 

 ared angustd. 

 Conch. Icon. Arca, pi. 15. f. 101. 



Hab. Islands of Buriąs and Corregidor, Philippines (found under 

 stones at lovv -vv'ater) ; Cuming. 



The sculpture of this shell is very similar to that of the Arca bul- 

 lata ; it is, however, of much finer character, although the shell is 

 more elongated and altogether larger. 



Arca ocellata. Arca testd elongato-quadratd, lateribus superne 

 angulatis, latere antico brevissimo, infra rotundato, postico elon- 

 gato, infra acuminato, margine ventrali bysso latissime Mante; 

 albidd, epidermide tenui, subsetosd, indutd ; radiatim striatd, striis 

 subtilissime crenulatis ; umbonibus remotis ; Ugamenti ared latis- 

 simd, rhombo ligamentario pecuUariter ocellato. 

 Conch. Icon. Arca, pi. 15. f. 102. 



Hab. Singapore (found in sandy mud at the depth of seven fa- 

 thoms) ; Cuming. 



This interesting little species exhibits a character which is quite 

 peculiar to the species. The dark ligamentary space between the 

 umbones is marked with a pair of oblique \vhite oval spots, one on 

 each valve. 



Arca Donaciformis. Arca testd sub-Donaciformi, medio leviter 

 coarctatd, latere antico brevissimo, truncato, postico elongato, sub- 

 acuminato ; albidd, epidermide vix nulld, striis transversis et lon- 

 gitudinalibus elevatis fimbriato-decussatd ,• Ugamenti ared antice 

 latiusctild, postice acuminatd ; ligamento brevi, ad posticam aree 

 partem solum adjuncto. 

 Conch. Icon. Arca, pi. 16. f. 104. 



Hab. Mozambiąue Channel (found imbedded in madrepore) ; 

 Hankey. 



The ligament and ligamentary area of this species present exactly 



