CLASS I. CRl'STACEA. 101 



Fani. I. PnRONYMAD.^. Lcoclis MSS. 



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

 the head. (Tuil fnrnislied with styles.) 



Genus 1. PIIRONYMA. . Lutr., Leach, Lamarck. 



Head large, nutant: antenna biarticulate, the first joint small : thorax 

 seven-jointed, all its segments bearing legs : /egs compressed, tzco 

 anterior pairs with the antepenidtimate joint furnished at its [)o:nt 

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

 and terminated with a small claw: Ihh-d and fourth pitirs simple, 

 longer, somewhat thicker, terminated by a bent claw: ffth pair 

 large, very long, thicker, didactyle ; the tirst 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 

 lingers cuned, and intf rnally furnished each with one tooth : sixth 

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

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

 pendice, placed on a peduncle : tail biarticidate, the first joint on 

 each side furnished with a biarticulate process, terminated by two 

 styles; second joint with four processes, each terminated by t'.vo 

 stj'les; the inferior processes biarticulate, the superior triarticulate. 



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

 and base of the fingers internally denticulated. 



Cancer sedentarius. Forsk. Fn. Arab. 95. Phronyma sedentaria. Latr. 

 Gen. Crust, et Lis. i. 57. Leuch, Edin. Enci/cl. vii. 403 — 433. — Trans. 

 Linn. Soc. xi. 353. Cancer (Gammartllus) sedentarius. Hcrbst, ii. 

 13G. t. 37. fg. 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, wlio 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. Gammaridj-. Leach's MSS, 



Body laterally' compressed : legs fourteen, with lamelliform coxae : 

 antenna four, inserted by pairs. (Jail furnished with styles.) 



Stirps 1. — Antenna: 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 sexei> subequal, monodactyle : upper antennas 

 shorter than the two first joints of the under ones. 



