150 



Var. a. Teatd nand, castaned albo strigatd, intits albd. 



Hab. ad Insulas Gallapagos. 



The examination of an extensive series has led Mr. Broderip to 

 the conclusion that this dwarf, and at first sight widely differing, 

 shell, is only a variety of Chama imbricata. The purple-brown is 

 changed into chestnut striped with white, and hardly any scales are 

 to be found on its wrinkled surface, except the double series which 

 crown the ridge on each side of the depressed line, and sometimes a 

 series or two on the affixed valve. This depressed line is not nearly 

 so well marked as it is in the large variety, but it is to be observed 

 on most of the specimens : some are absolutely without imbrications. 



This variety was found attached to rocks and stones at low water. 



Chama producta. Chama testd subpurpured, crebei'rirn^ lamel- 

 losu, lamellis foUaceis, integris ; valvd inferiore enormiter pro- 

 ductd ; limbo integro, purpurea. 



Hab. ad Mexico. (Gulf of Tehuantepec.) 



The interior of the shell, which has something of the aspect of 

 that of a Gryphaa, is white tinged with yellowish, and striped in the 

 direction of the lamella with purple. The purple border on the 

 smooth internal edge of the upper valve is of some width. 



Dredged up from sandy mud at a depth of ten fathoms, attached 

 to stones. 



Chama cobrugata. Chama testd eorrugatd, ruhro-purpured albo 



vurid ; intiis atro-purpured, limbo integro. 

 Hab. in America Centrali. (Real Llejos.) 



Found attached to stones at low water. All the specimens which 

 Mr. Broderip had seen turn from right to left. 



Chama echinata. Chama testd albidd purpurea varid, spinis 

 fornicatis echinatd ; intiis atro-purpured vel sub-rubrd, limbo 

 integro ; dente cardinali rubro. 



Hab. in Americfi Centrali. (Puerto Portrero.) 



The spines of this species, which are close set and well developed 

 in youth, are entirely abraded in age, till nothing but corrugation is 

 left externally. But as the animal advances in life the interior of 

 the shell is richly painted, till in old age it arrives to an intensity of 

 dark purple that it is hard to imitate with colours however rich. 

 At this period the cardinal tooth becomes of the hue of the bone of 

 the red Coral (Isis nobilis) used for ornamental purposes. 



Found at low water attached to rocks. 



Chama spinosa. Chama testd albd interdum roseo vel purpurea 

 umbonem versus valva super ioris pictd, spinis fornicatis creberri- 

 mis horridd ; intiis albd. Umbo integro. 

 Hab. in Oceano Pacifico. (Lord Hood's Island.) 

 This pretty species was di'edged up, attached to corals and Avicula, 

 at a depth ranging from three to seven fathoms. The younger spe- 

 cimens are tinged towards the umbo of the upper valve with a deli- 

 cate rose-colour. The umbo of the lower valve is often produced 

 after the manner of that of Chama unicornis. Lam. 



