200 Mr. Frembly on some species of Chit ones 



This species grows to a large size ; one in my possession mea- 

 sured when alive upwards of four inches in length ; but the ge- 

 neral size is about three inches. We have observed amongst 

 these a variety much narrower than the generality of thenij but not 

 differing in any other respect from the above description. 



This is not given here as a new species, a specimen from the 

 Tankerville Collection, now in the possession of the Rev. Dr. 

 Goodall, agreeing so nearly with mine, that there can be no doubt 

 but they are of the same species. It has, I understand, been 

 called C. latus^ but that term would not be applicable to both 

 varieties. I have therefore taken the liberty of naming it from 

 its colour, to which I am aware there are many objections, nor 

 would it have been adopted but from the unvarying hue I have 

 observed to run through the whole of the specimens which haves 

 passed under my notice. 



Amongst the very young shells, I observe that some of them 

 have their borders of a lighter colour than their shells, and spotted 

 with black ; this not being a constant character in all the young 

 specimens, they may be regarded as a variety. 



5. Chiton granosus, 



C. test^ oblongo-ovat^, crassiuscula, nigrescenti, fasciis duabus 

 longitudinalibus, subcentralibus albidis : valvis duabus termi- 

 nalibus (interdum radiatim) granosis; areis valvarum centrali- 

 bus longitudinaliter striatis, lateralibus granoso-radiatis. 



Tab. Supp. XVII. f. 1. 



Shell oblong ovate, thick, opaque, glossy, brownish black; 

 dorsal valves having a dirty white longitudinal band on each side 

 of the beaks : inside blackish green. Valves eight ; anterior 

 with numerous raised concentric granulations; second valve acute- 

 ly beaked, and finely carinated, the five following with a broad 

 polished dorsal line : dorsal valves divided into three compart- 

 ments, the front finely reticulated, the others with prominent 

 granulations extending from the beaks to the lateral margins; 

 posterior valve granulated like the anterior. Border thick, rather 

 broad, covered with dull black granula, divided into two parts. 



