CLASS r. CRUSTACEA. lOl 



Fain. I. PiiRONVMAD.TE. Leach's MSS. 



Legs fourteen : antenna two, inserted one on each side of the front of 

 the head. (Tail furnished with styles.) 



Genus 1. PHRONY^NIA. Lafr., Leach, Lamarck. 



Head large, nutant: autcunte biarticulate, the first joint small : tharav 

 seven-jointed, all its segments bearing legs : legs compressed, fmo 

 anterior pairs with the antepenultimate joint furnished at its point 

 with a foliaceous process ; the penultimate joint with the point bifid 

 and terminated with a small claw : third and fourth pahs simple, 

 longer, somewhat thicker, terminated by a bent claw: Jlf/h pair 

 large, very long, thicker, didactyle ; the first joint gradually thick- 

 ened towards its point; the second subtrigonate; the third ovate, 

 and abruptly narrowed at its base ; the last narrowed at its base ; the 

 fingers curved, and internally furnished each with one tooth : sixth 

 and seventh pairs simple, terminated with a nearly straight claw : 

 abdomen triarticulate, each segment, on each side, with a double ap- 

 pendice, placed on a peduncle : fait biarticulate, the first joint on 

 each side furnished with a biarticulate process, terminated by two 

 styles ; second joint with four processes, each terminated by two 

 styles ; the inferior processes biarticulate, the superior triarticulate. 



Sp. 1. Phron. sedentaria. Fifth pair of legs with the apex of the thumb 

 and base of the fingers internally denticulated. 



Cancer sedentarius. Foi-sk. Fn.Arab. 95. Phronyma sedentaria. Latr. 

 Gen. Crust, et Lns. i. 57. Leach, Ec/in. Lnctjcl. vii. 403 — 433. — Trans. 

 Linn. Sac. xi. 355. Cancer (Ganunai-ellus) sedentarius. Herbst, ii. 

 136. t. ol.fig. 8. 



Inhabits the Mediterranean Sea and Zetland Sea, residing in a cell 

 composed of a gelatinous substance, open at each extremity, where 

 it sits in an incurved posture. 



The only specimen of this most interesting, rare, and curious 

 animal was taken by the Reverend Dr. J. Fleming, one of our most 

 zealous naturalists, who found it on the 3d of November 1809, at 

 Burray in Zetland, amongst rejectamenta of the sea, and communi- 

 cated it to Dr Leach. 



Fam. II. Gammarid^:. LxaclCs MSS. 



Bof/(/ laterally compressed: legs fourteen, with lamelliform coxse : 

 antennce four, inserted by pairs. {Tail furnished with styles.) 



Stirps 1. — Antennae four-jointed, the last segment composed of many- 

 little joints ; the upper ones very short. 



Genus 2. TALITRUS. Latr., Base, Leach. 

 Four anterior legs in both sexes subequal, monodactyle : upper antenna 

 shorter than the two first joints of the under ones. 



