PEDICKLLATA. 393 



spines ; the little fleshy feet also issue from each side between the 

 origin of those spines *; and 



Those in which there arc none of these lateral spines, but where 

 the rays are covered with imbricated scales, and resemble tails of sei*- 

 pents. The central disk, in each interval of its rays, and on the 

 side where the mouth is placed, is marked by four holes which ex- 

 tend into the interior of the animal, serving perhaps for respiration, 

 or, according to the others, for the issue of the ova. Their only feet 

 are in five short grooves, which form a star round the mouth f. 



The GoRGONocEPHAL^, Leach +, called Eurtales by M. de La- 

 marck, are those in Avhich the rays are dichotomously divided. In 

 some this division commences at the base of the rays, presenting the 

 appearance of a bimdle of serpents — they are commonly called Me- 

 dusa's Head%. There are two preceding holes at the base of each 

 ray. 



In others, however, this division only commences at the end of the 

 rays, and is not often repeated ||. 



We should also separate the 



Alecto of Leach, called Comatula by M. de Lamarck. They 

 have five large articulated rays, each of which is divided into two or 

 three, bearing two ranges of articulated threads ; these five rays are 

 attached to a petrous disk, also furnished, on the side opposite to the 

 mouth, with one, two, or three ranges of articulated threads without 

 branches, shorter and more slender than the large rays, and by which 

 tlie animal is said to fix itself. The sac which contains the viscera 

 is situated in the centre of the large rays, opening by a stellated 

 mouth and a second and tubular orifice which may be the anus ^. 



It is in the vicinity of the Comatula that we must place the 



Encirnus, Gnett.**, 



Which might be defined ff as Comatulae with a prolonged disk and a 

 multiarticulated stem. The branches themselves are articulated and 

 dichotomously ramose, bearing ranges of articulated threads ; the 

 stem being furnished with smaller ones at different heights; the 

 mouth is in the centre of the rays, and the anus on one side. 



* Ast. nigra, Miill., Zool. Dan., d, XCIII ; — A. tricolor, lb., XCVII ; A.fragilis, 

 lb,, XC\\\l\—A.fiHformis.^ lb., LIX ; — A. aculeata. Link., XXVI, 42 ; Miill.', 

 Zool. Dan., XCIX ; — Ophiura echinata, Lara.; Encyc, CXXIV, 2, 3; — Oph. ciU- 

 oris, lb., 4, 5 ; — 02)h. luinbricalis, lb., 1. 



t Asterias ophiura, L. ; Ophiura lacerta,, Lam., Encyc, CXXIII, 1, CXXII ; 



Oph.texturafa, Id. ; Link., II., 4 ; Encyc. CXXIII, 2, 3 ; — Oph. cuspidifera, Lam > 

 Encyc, CXXII, 5— 8. 



X Zool. Miscel., No. 16, p. 51. 



§ Asterias caput Meduste L. ; (Euri/ale asperum) Lam. ; Link., XX, 32 ; Encyc. 

 CXXVII ;—Eurtjale muncatum, lb., CXXVIII and CXXIX ;— Asterias eurmle, Gm" 

 {Euryale cosiosum) lb., CXXX ; Link., XXIX and XXX. 



II Euryale palmiferum, Lam., Encyc, CXX VI. 



^1 Asterias multiradiuta, Zool. Miscel., loc. cit., L, ; Link.. XX, 33, XXII, 34- 

 Encyc. CXXV ; — Ast. pectinatu, L; Link., XXXVII, 66 ; Encyc. CXXIV, 6 Effvnt' 

 Echin. I, 1, 2, &c ' * 



** Acad, des Sc, 1755, p. 224. 



ft See Schweigger, Hist. Moll, et Zooph., p. 528. 



VOL. IV. D D 



