APPENDIX. 313 



together by lateral anastomoses ; and there is an oblong space 

 marked out by a red vessel. Anterior end narrow, sHghtly dilated 

 at the apex into a spoon-shaped sucker; the aperture terminal. 

 Eyes eight, in four pairs in a linear series down the neck, the first 

 pair smaller and approximated ; each eye or pair surrounded by a 

 pale halo. Anal sucker proportionably small, circular. Sides cre- 

 nulate. 



This beautiful leech varies considerably in colour and in the degree 

 of its transparency. The crucial markings are sometimes faintly 

 marked or obsolete, but the oblong system of blood-vessels over the 

 sucker becomes then more obvious. The body is usually marked 

 very prettily with four rows of white circular dots down the back, 

 equally distanced ; and the granules of the rings are so arranged 

 that they also form a regular series of longitudinal rows. It seems 

 naturally a sluggish species, and likes to congregate in clusters, 

 which have a disagreeable appearance from the gelatinous consistence 

 of the worms. It moves by attaching the oral end, and trailing the 

 body onwards, without raising it from the surface of the ground. 

 It likes to remain stationary, waving the body by a series of wide 

 undulations ; but it cannot swim. When fully contracted, the body 

 is almost round, with a short apiculus formed by the projecting 

 snout. It does not willingly leave the water. 



Holy Island Lough, plentiful. Coldingham Lough, Sir J, G. 

 Daly ell, who says that it is "rarely disseminated in Scotland." He 

 also tells us that it is frequently in motion, and one specimen " could 

 not be said ever to rest." The nature of its food is somewhat un- 

 certain*. The ova are produced after the manner of its genus. 



** The figure of the Chequered Leech, at rest, is the longitudinal 

 half of a pear, between five and six lines in length, by about the same 

 in width across the longest diameter ; when extended, it stretches 

 about two inches and a quarter, when the width at the base is three 

 lines, and the diameter of the sucker one line. The anterior extre- 

 mity, when extended, is somewhat of a long lanceolate form, with 

 four pairs of black eyes down the middle, very distinct, the outer 

 pair rather smaller than the others. The body is environed by a 

 broad, thin, crenate, not chequered margin, with a row of yellow 

 tubercles. 



"The body is divided into segments somewhat broad, and divided 

 by narrow circles. Its substance is wholly gelatinous— quivering 

 with the slightest motion. 



" This is infinitely the finest and most beautiful of the Scottish 

 leeches, generally of a fine translucent green, speckled black and 

 yellow. Sometimes there appear several longitudinal rows of yellow 

 specks interspersed with black specks ; sometimes all are disposed 

 with less regularity." 



"The colour undergoes considerable variation. It fades as the 



* Mueller believes that it sucks the blood of fishes and of frogs. It did not 

 attack the mollusca which were given to it. It hatches, as it were, the eggs, 

 which are of a deep yellow colour. — Jspectum, &c., p. 22. 



