108 MODERN SYSTEM, 



Genus 21. N^TLSA. Leach. 



Tall oil each side of the last segment, with a straight siibcompresscd 

 process attached to a peduncle : boch/ six-jointed, the last joint largest: 

 antennte setaceous, subequal ; upper ones with a very large biarticu- 

 lated pedimclc, the first joint largest: space between the antennae 

 easily to be discerned : claus bifid. 



Sp. 1. A«. hidentata. Last segment of the body armed with two spines 

 or teeth ; colour cinereous, faintly streaked with blue, or reddish. 



Oniscus bideiuatus. Adann;, Trans. Linn. Soc. v. 8. t. 2./ 3. Nacsa hi- 

 dentata. Leach, Edin. Encycl. vii. A05.— Trans. Linn. Soc.xi. 367.— 

 Supp. to Emyc/. Brit. i. 427. 



Inhabits the coasts of Wales and Devonshire. 



Stirps 2. Tail with t^vo laraellje on each side. 



* Superior antennte nitli a very large peduncle. Claus bifid. 



Genus 22. .CYMODICE. Leach. 



Eyes touching the anterior margin of the first segment of the body : 

 '/joo'y seven-jointed: tail at the base, on each side with two subcom- 

 pressed Init not foliaceous appendages, the exterior ones largest; the 

 apex of the tail notched, with a lamella in the centre: clau^s bifid. 



Sp. 1. Cy.tnincata. Apex of the tail truncate. 



Oniscus truncaUis. Montagus MSS. Cymodice truncata. Leach, Edin. 

 Encycl. vii. 433. — Trans. Linn. Soc. xi. 303. — Snpp. to Encycl. Brit. 

 i. 127. 



This species is very rare, and has been found but tliree times on 

 the southern coast of Devonshire. 



Genus 23. DYNAMENE. Leach. 

 Eyes not reaching to the anterior margin of the first segment of the 

 "^body: body seven-jointed: tail wkh two equal foliaceous appendages 

 on each side of its base ; the apex notched : clazcs bifid. 

 Dvnamene. Leach, Edin. Encycl. vii. 433. 



There are several indigenous species cf this genus, and their cha- 

 racters will be given under the article Cymothoade'es, in the Di£- 

 tionnaire des Sciences Natu/xlles, by Dr. Leach. 

 Genus 24. SPILl-LROMA. Latr., Leach. 

 Eyes not reaching to the anterior margin of the first segment of the 

 body : body seven-jointed : tail with its apex entire ; the base on each 

 side with two equal foliaceous appendages: claws bifid. 

 Sp. 1. Sph. scrruta. Body smooth, unarmed: tail very smooth on each 

 side; obli(|uely truncated : lamella; elliptic, acute, the external ones 

 externally serrated. 

 Oniscus Globator. Pall. Spec. ZooLfasc. ix. t. 4. /. 18. Cymothea ser- 

 jata. Eabr. Ent.Syst.u. b\0. Sphperoma cinerea. Latr. Gen. Crust. 



