CRUSTACEA. 179 



C. oestrum, Leach. (Oniscus, Lin.) Head square, transverse, nar- 

 rowed at the extremity ; carinae of the last eight thighs projecting 

 at their base. Inhabits European seas Desm. Crust. 309. 



Gen. 3. MGA, Leach. 



Two first joints of the upper antennae broad and compressed ; 

 eyes large, slightly convex ; tail with its appendages folia- 

 ceous ; sides of the joints of the abdomen imbricated. 



JE. emarginata, Leach. Last joint of the abdomen laterally dilat- 

 ed, and the extremity pointed ; interior lamella obliquely trun- 

 cated internally, the extremity notched exteriorly Sup. Encyc. 

 Brit. i. pi. 21. 



IE. tridens, Leach. Last joint of the abdomen with three carinae 

 prolonged beyond the extremity in the form of teeth. Inhabits 

 Scottish seas. Linn. Trans, xi. 370. 



Gen. 4. CIIIOLANA, Leach. 



Abdomen composed of six joints ; eyes granulated ; posterior 

 appendages with the external lamina longer and broader than 

 the internal one. 



C. Cranchii, Leach. Body smooth, dotted, the last segment of the 

 abdomen triangular and rounded at its extremity. Inhabits Brit- 

 ish coasts Desm. Crust. 303. 



Gen. 5. EUTIYDICE, Leach. 



Abdomen composed of five joints ; eyes distinct, simple, late- 

 ral ; head as broad as the first segment of the body. 



E. pulclira, Leach. Body cinereous, variegated with black, smooth ; 

 abdomen with the last segment semi-oval. Inhabits coasts of 

 Britain. Linn. Trans, xi. 370. 



Gen. 6. NELOCIRA, Leach. 



Abdomen composed of five segments ; eyes granulated ; poste- 

 rior ventral appendages with the external laminae larger than 

 the internal. 



N. Smainsoni, Leach. Body smooth, dotted; abdomen with the 

 last joint triangular ; sides slightly arched, the point rounded. 

 Inhabits Mediterranean sea. Desm. Crust. 302. 



Gen. 7. LIMNORIA, Leach. 



Body cylindrical ; eyes granulated, and formed of smooth ap- 

 proximated ocelli ; head as broad as the first segment of the 

 body ; four antennae inserted in the same line ; two lamellae 

 at the caudal appendages ; last segment of the abdomen sub- 

 orbicular. 



L. terebrans, Leach. Body cinereous ; eyes pitchy black. 1 line 

 long. Piles of wood in the British seas. Lin. Trans, xi. 370. 

 The female is about a third larger than the male. This small animal was first 

 seen by Dr Leach in submerged wood used in the erection of the Bell Rock Light- 

 house ; and it was afterwards discovered that the piles of the Chain Pier at Newhaven 



