GRUSTACEA. ; 661 
many filaments set pectinately on a peduncular cirrus; last pair ter- 
minated by two lamine oval, depressed, forming the pinna of tail. 
Squilla Fapr. (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. Branchiz 
distinct adhering to the first five pairs of abdominal feet. 
Comp. LatTREILLE Encycl. méth., Hist. nat., Ins. Tom, X. pp. 467—475. 
Coronis Latr. Six last feet of trunk with appendage oval, plane, 
membranous. 
Sp. Coronis scolopendra Latr., GUERIN Iconogr., Crust. Pl. 24, fig. 2, &e. 
Squilla Latr. (and Gonodactylus ejusd.). Six last feet of trunk 
with appendage elongate, styliform. 
Sp. Squilla scyllarus FaBr., Rumpuius Amb. Rariteitkam. Tab. 11. fig. F ;— 
Squilla chiragra Hersst, Krabben, Tab. 34, fig. 2, LAarREILLE Lncycl. 
méth., Crust. et Ins. Pl. 325, fig. 2. 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. Pl. 41, fig. 2, from the Medi- 
terranean, Squilla maculata Rumeu. Tab. cit. fig. E, from the Mo- 
luceas, &e. 
Squillerichthus Epw. 
Erichthus Latr., Smerdis Leach. Shell of cephalothorax not 
sulcate, produced over the last three segments of trunk. Rudi- 
ments alone of branchiz, adhering to the first pair of caudal feet, or 
branchiz none distinct. 
Sp. Frichthus vitreus Latr., Squilla vitrea Fasr., Smerdis vulgaris LEacu, 
Dersm. Crust. Pl. 44, fig. 2, &c. 
Alima LEACH. 
Comp. on this and the preceding genus, LeacH in TuckEy’s Narrative 
of an Expedition to explore the river Zaire. London, 1818, 4to, pp. 415, 
416, and fig. Pl. x1. 
Family XXV. Bipeltata. Cephalothoracic shield membranous, 
pellucid, produced over the segments of trunk. Middle antenne 
terminated by two filaments. Six pairs of feet slender, elongate, 
furnished with a cirrus multiarticulate, pilose. 
