NEPHELIS. — TROCHETA. 45 



yellowish quadrangular spots arranged in a regular pattern. The 

 ventral surface is olivaceous or reddish-brown, unspotted. At certain 

 seasons there appears, on the anterior third of the body, a broad belt 

 or clitellus, most apparent on the belly ; and in the middle of it 

 there is the orifice whence the ova are excluded. The young are 

 greyish, with dusky interranea forming an ill-defined fascia along 

 each side. 



Miiller and Moquin-Tandon have characterized twelve varieties 

 from the peculiar patterns on which the colours are disposed ; and 

 four of these Savigny has described as distinct species. I have 

 found three of them in Coldingham Lough. 



(a) The Whiteadder, Berwickshire, Dr. Johnston. 



5. TROCHETA. 



Trocheta, Moq.-Tandon, Monogr. 308. Dies. Syst. Helm. i. 459. 

 Trochetia, Lam. An. s. Vert. v. 291. Blainville in Diet, des Sc. nat. 



xlvii. 244. Cuv. Regn. Anim. iii. 215. 

 Geobdella, Blainville in lib. cit. xlvii. 244, & Ivii. 559. 



Char. Body elongate, flattish, smooth, acephalous, composed of 

 numerous subequal narrow segments separated by a simply impressed 

 line : mouth large, oblique, with the thick prominent obtuse upper 

 lip curling over it : eyes 8, small, the front row lunate, the hinder 

 one transverse : sexual orifices between the 32nd and 33rd, and be- 

 tween the 37th and 38th rings : vent large, semilunate : anal sucker 

 of medium size, attached in the centre, directed ventrally. Ova in 

 coriaceous capsules, free, deposited in moist ground. 



1 . T. subviridis. 



Trochetia subviridis. Lam. An. s. Vert. v. 292; 2de edit. v. 523. 



J. E. Gray in Ann. Sf Mag. Nat. Hist. ser. 2. vii. 429. 

 Geobdella de Dutrochet, Blainville in Diet, des Se. nat. xlvii. 246, 



Ivii. 559, Atlas pi. Hirudin, f. 6. Egidy, Bluteg. 109. 

 Trocheta subviridis, Moq.-Tandon, Monogr. 309. pi. 4, fig. omn. Dies. 



Syst. Helm. i. 459. 



Hab. Boggy ground, subterranean ditches and runlets. Feeds on 



the earth-worm. 



Obs. The specimen in the Museum was, when alive, more than 

 7 inches long. It is yet fully 6, and ^ an inch in diameter. The 

 dorsal surface is of a uniform dull greenish-grey colour ; the ventral 

 a shade lighter, and more muscular. The rings are narrow, nearly 

 equal, marked by a simply impressed separating line, and not crenu- 

 late on the margins. The mouth is large, transverse, sub triangulate, 

 with a thick muscular overlapping upper lip, which is somewhat 

 crisped. There is a blackish fascia across the front above the lip, 

 but I can detect no eyes ; and Moquin-Tandon says that they are 

 frequently difficult to be seen, and are sometimes absent. About an 



