Dr. H. A. Nicholson on Dredgings in Lake Ontario. 279 



ticus^ and larvae of CMronomus^ Lihellula^ &c.), and a large 

 number of young fishes {Pimelodusj Perca, &c.). Numerous 

 Terrapins were also observed, and a single specimen of Meno- 

 iranchus ; but the latter unfortunately was not secured. 



In the following list are indicated the chief forms of animal 

 life which were obtained in these dredgings. As before re- 

 marked, time has in most cases not permitted of any specific 

 determinations being made, and the species will be described 

 at length in a subsequent notice. The microscopic species 

 also liavCj in the meanwhile, been completely neglected. 



Annelida. 



1. Nephelis^ sp. 



A small leech, nearly an inch in length when at rest, with 

 an oblique posterior sucker, and of a liver-brown colour in life. 

 Nearly allied to, if not identical with, N. latei-alis, Say. 



Rare in 3 fathoms, Toronto Bay. 



2. Nephelis, sp. 



An exceedingly remarkable form, apparently undescribed. 

 The body is much flattened, and the width is nearly as great 

 as the length when the animal is at rest. Length | inch in 

 extension, I inch or less in contraction. Colour sometimes 

 dark greenish brown or nearly black, sometimes light brown, 

 with innumerable black points and numerous yellow spots, 

 which are especially abundant at the margins. A double black 

 dorsal line. The habits of this little leech are very remarkable. 

 The adult leech usually places itself with its entire ventral 

 surface closely appressed to some foreign body, such as a stone 

 or dead shell, to which it adheres like a limpet or small Chiton. 

 When forcibly detached or irritated it rolls up like a hedgehog 

 or like the Myriopods of the genus Glomeris. The objects 

 served by these peculiar habits become obvious when it is seen 

 that almost every individual carries attached to the ventral 

 surface of the body a large number (generally from twenty to 

 thirty) of young leeches. The young are attached to the ven- 

 tral surface of the parent posteriorly in a close cluster, which 

 is surrounded on all sides by a vacant space ; they adhere to 

 the adult by their posterior suckers, Avhich are separated from 

 the body by a very distinct constriction. The young leeches 

 are about -^ of an inch in length, in colom- light yellow or 

 reddish, and semitransparent. The stomach is very conspi- 

 cuous, and fills the greater part of the body ; but no other in- 

 ternal organs could be detected. This extraordinary habit of 

 carrying the young has been noticed by Verrill in a species of 



