I 



APPENDIX. 317 



two black almost coalescent eyes ; and behind them is a brownish 

 spot marking the extremity of the retracted proboscis. Sucker 

 ventral. 



Glossiphonia flava (page 53). 



" The length of the specimens of this species, when quiescent, was 

 from six to more lines ; when extended, about fourteen lines. General 

 form not unlike the medicinal leech. Form of the head lanceolate 

 or trout-shaped. Eyes two, black, in front. The viscera consist of 

 thirteen pairs of transverse sacs, sufficiently conspicuous in some spe- 

 cimens. The body is composed of numerous segments slightly in- 

 dented. The predominant colour is yellow, sometimes very vivid, 

 sometimes dusky ; and there are specimens whose contrasting hues 

 expose four longitudinal rows of beautiful yellow spots, running down 

 the whole back to the sucker, which itself has a marginal circular 

 row. Under the microscope, these, so ornamental to the eye, prove 

 to be only irregular transverse short marks. 



" Though the general form of the animal, while quiescent, corre- 

 sponds with that of the medicinalis, it is not so thick, plump, and 

 heavy as the tessellata, nor alike tremulous. Also some of the 

 young at an early stage appear quite cylindrical. 



"Much of the beauty of this animal depends on the colour. 

 Besides the four rows of yellow spots down the whole back, there is 

 a marginal row on each side, which can be seen from below." Breeds 

 chiefly from May until August, and presents no specific peculiarity 

 in this respect. 



Glossiphonia vitrina (page 53). 



Brightwell and Dalyell found each a single specimen only. " Our 

 specimen," says Mr. Brightwell, "is nearly cylindrical, about an 

 inch long, the posterior disk larger than the anterior ; eight eyes, 

 in two rows of four each ; colour green, with two indistinct, whitish, 

 longitudinal series of spots above, and two spots underneath ; the 

 whole body, magnified, appears studded with small, dark, irre- 

 gular specks." The abdomen was covered with young, "which 

 adhered solely by the posterior disk. We kept this specimen from 

 the 24 th of June to the 28th of August, when it died. The young 

 remained attached to the parent during all this time, and we took 

 some pains to ascertain their exact number, and found they amounted 

 to 143. We never saw the parent or the young ones take any food. 

 The young differed altogether in colour from the parent, the latter 

 being a deep green, the former a light ash-colour. The eyes of the 

 parent could scarcely be discerned with a lens ; the eyes of the young 

 were very conspicuous, and could be seen with the naked eye. The 

 motion of this species is geometrical, and it never swims. The abdo- 

 men of the parent had no pouch, but was much expanded by the 

 adhesion of so numerous a progeny ; so much so, as to make the form 

 appear very different to the young." 



