150 



Var. a. Teshl nand, castaned albo strigatd, intus 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 Chamą hnbricata, The purple-bro\vn is 

 ehanged 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 afExed valve. This depressed line is not nearly 

 so ■vvell 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 vvater. 



Chamą producta. Chamą testd subpurpured, creberrinii lamel- 

 losd, lamellis foliaceis , integris ; valvd inferiore enormiter pro- 

 ductd ; limbo integro, purpureo. 



Hab. ad Mexico. (Gulf of Tehuantepec.) 



The interior of the shell, vi'hich has something of the aspect of 

 that of a Gryphcea, is white tinged with yellovirish, 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. 



Chamą cobrugata. Chamą testd corrugatd, rubro-purpured albo 



varid ; intiis atro-purpured, limbo integro. 

 Hab. in Americž C'entrali. (Real Liejos.) 



Found attached to stones at \owf ■vvater. Ali the specimens which 

 Mr. Broderip had seen turn from right to left. 



Chamą echinata. Chamą testd albidd purpureo varid, spinis 

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

 integro ; dente cardinali rubro. 



Hab. in Americ^ Centrali. (Puerto Portrero.) 



The spines of this species, which are olose 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 \vith colours hovvever rich. 

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

 the red Coral {Isis nobilis) used for ornamentai purposes. 



Found at low water attached to rocks. 



Chamą spinosa. Chamą testd albd interdum roseo vel purpureo 

 umbonem versus valva superioris pictd, spinis fornicatis creberri- 

 mis horridd ; intus albd, limbo integro. 

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

 This pretty species \vas dredged 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 -tt-ith a deli- 

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

 after the raanner of that of Chamą unicornis, Lam. 



