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 formiiig an ill-defined fascia along 

 each side. 



MilUer and Moquin-Tandon have jcharacterized 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 WHiiteadder, Berwickshire, Br. Johnston. 



5. TEOCHETA. 



Trocheta, Moq.-Tandon, Monogr. 308. Dies. Syst. Helm. i. 45.9. 

 Troclietia, Lam. An. s. Vert. v. 291. Blainville in Diet, des Sc. not. 



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 Dutrocliet, 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. 



Hah. 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, subtriangulate, 

 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 



