OF THE LINN^AN GENEEA. 

 OEDER FIRST. 



MULTIYALVE SHELLS. 



Animah soft, of a simple structure, and covered with a 

 calcareous habitation or shell, formed of several pieces. 



Genus 1— CHITON. 



Animal a Doris ; shell consisting of several segments or 

 valves, placed transversely on the back of the animal, and 

 lying upon each other at their anterior edge. 



Chiton maryinatus. — The Marginated Chiton. Plate 

 V. fig. 1. With eight carinated valves, projected over each 

 other in the form of a beak; very finely shagreened, and 

 having a broad margin, of a dusky or ash-coloured brown ; 

 ^ths of an inch long. Inhabits the British seas, upon stones. 



The animals of this genus are marine, adhere to rocks and stones, 

 in general near low water-mark, and are, at first view, very like an 

 Oniscus, or the small crustaceous animal called a Slater, or Wood- 

 louse. 



Genus 2 LEPAS. 



Animal a Triton; shell affixed at the base, and consisting 

 of many unequal erect valves. 



Lepas rugosa — The Rough Lepas. Plate I. fig. 1. 

 (Balanus rugosus, Lamarck.) With a sub-cylindric shell, 

 having usually six furrows, which fretiuently widen towards 

 the top, and terminate in angulated points, sometimes as 

 wide as at the base; compartments sulcated, often striated 

 longitudinally; of a yellowish colour; operculum consisting 

 of four rough, angulated, erect valves 



