CRUSTACEA. 661 



many filaments set pectinately on a peduncular cirrus; last pair ter- 

 minated by two laminae oval, depressed, forming the pinna of tail. 



Squilla FABR. (in part). Cephalothoracic shield tripartite from 

 two longitudinal furrows, not covering the last segment of trunk 

 at least, mostly not covering the three last segments. Branchiae 

 distinct adhering to the first five pairs of abdominal feet. 



Comp. LATKEILLE Encycl. meth., Hist. nat. y Ins. Tom. x. pp. 467 475. 



Coronis LATH. Six last feet of trunk with appendage oval, plane, 

 membranous. 



Sp. Coronis scolopendra LATB., GU^RIN Iconogr., Crust. PI. 24, fig. 2, &c. 



Squilla LATE, (and Gonodactylus ejusd.). Six last feet of trunk 

 with appendage elongate, styliform. 



Sp. Squilla scyllarus FABR., EUMPHIUS Ami. JRariteitJcam. Tab. in. fig. P ; 

 Squilla chiragra HERBST, Krabben, Tab. 34, fig. 2, LATREILLE Encycl. 

 meth., Crust, et Ins. PL 325, fig. i. These species, in which the terminal 

 joint of the shears is almost or entirely toothless and swollen at the base, 

 form the genus Gonodactylus LATR. In most species this joint is small, 

 curved and densely toothed within. As, for example, Squilla mantis FABR. 

 (Cancer mantis L. in part), DESMAR. Crust. PI. 41, fig. 2, from the Medi- 

 terranean, Squilla maculata HUMPH. Tab. cit. fig. E, from the Mo- 

 luccas, &c. 



Squitterichthus EDW. 



Erichthus LATR., Smerdis LEACH. Shell of cephalothorax not 

 mlcate, produced over the last three segments of trunk. Kudi- 

 lents alone of branchiae, adhering to the first pair of caudal feet, or 

 ichiae none distinct. 



Sp. Erichthus vitreus LATR., Squilla vitrea FABR., Smerdis vulgaris LEACH, 

 DESM. Crust. PI. 44, fig. 2, &c. 



Alima LEACH. 



Comp. on this and the preceding genus, LEACH in TUCKET'S Narrative 

 of an Expedition to explore the river Zaire. London, 1818, 4to, pp. 415, 

 416, and fig. PI. XI. 



Family XXV. Bipeltata. Cephalothoracic shield membranous, 

 illucid, produced over the segments of trunk. Middle antennas 

 linated by two filaments. Six pairs of feet slender, elongate, 

 lished with a cirrus multiarticulate, pilose. 



