ZOOLOGICAL AND BOTANICAL ASSOCIATION. 197 



For the means of describing the following genera I am indebted to 

 the courtesy of Adam White, Esq., of the British Museum, who kindly- 

 permitted me to take the necessary notes and figures from specimens in 

 that collection. 



Family. (?) 



Genus. — Acanthoniscijs (A. White; Gosse's "Jamaica"). 



Body somewhat globose ; head rounded ; no true median or lateral 

 lobes ; a pair of small spurious lateral lobes beneath orbits, arising from 

 production of antennary ring ; external antenna? (?) ; internal antennae 

 three-jointed. 



Cephalothorax : coxae well marked. Abdomen : coxae of first and 

 second somite obsolete ; third to fifth narrow. 



Telson: coxae obsolete ; posterior pleopods (false feet) nearly unco- 

 vered; peduncle (basis) somewhat triangular, broad; accessory lobe 

 badly marked ; accessory appendage inserted nearly on same line with 

 ischium, flattened, rounded at the extremity ; ischium long subulate. 

 Species, A. spiniger. 



Acanthoni8cu8 spiniger. {A. White, "Brit. Mus. Cat.," p. 99.) 



Body covered over with long spines arranged in a double longitu- 

 dinal row, one spine to each ring. In cephalothorax a second row of 

 shorter spines (two to each ring) on each side at junction of coxae and 

 body. 



Head covered with coarse knobs; two minute spines behind; a 

 raised emarginate ridge marks out front. 



Coxae of first cephalothoracic somite expanded into a circular lobe ; 

 coxae of second to sixth somite narrow ; seventh, somewhat quadrila- 

 teral. 



Abdominal somites : coxae, first and second, obsolete ; third, fourth, 

 and fifth, narrow, curved, triangular. 



Telson cordato-panduriform, apex deeply notched, its extremities 

 triangular, produced, acuminate ; sides of telson deeply incurved at 

 base, and then broadly convex. Posterior pleopods : accessory fila- 

 ment somewhat flattened ; rounded at the extremity, about half length 

 of ischium, and arising from a point distant from apex about a third of 

 total length of peduncle. Ischium long and subulate. Peduncle pro- 

 longed as ;i spinr external to origin of isrhium. 



