-'57 



HIRUDINEA. 



BY 



W. A. HARDING, M.A., F.L.S. 



LITTLE is known of the Hirudinea of the Antarctic ami Subantarctic Zones. The leeches 

 collected by the "Terra Nova" Expedition were therefore not likely to he wanting 

 in interest ; and in fact, although few in number and representative of but one species, 

 this species proves to be a new one and referable to a new iienus <>|' [chthyobdellidae. 



According to information .sent with the material this leech is a fish parasite. 

 the seven specimens having been taken at the Winter Quarters, Victoria Land, on two 

 occasions (May 10th and May 16th, 1911), from the gills of fishes of the genus 

 Trematomus, probably either '/'. /nu/^m/i. or T. bernacchii, both of which are widely 

 distributed on the coasts of Antarctica. 



I proceed to give a short diagnosis of the new Ichthyobdellid genus together with 

 a description of the new species on which it is founded. 



SUB-ORDER RHYNCHOBDELLAE 

 FAMILY K 'HTHYOBDELLIDAE 



CRYOBDELLA, gen. uov. 

 , icy cold ; /3SeX\a, leech.] 



Small marine leeches parasitic on the gills of fish. Without eyes. Body fusiform. 

 little flattened, smooth. Without pulsating vesicles. " Complete " somite formed of 

 three rings which in the posterior part of the body are sub-divided into six. Last pair 

 of crop caeca partly fused together. Four pairs of testes. 



CRYOBDELLA LEVIGATA, sp.n. 



. Body long, slender and tapering from the slightly swollen middle portion towards 

 either extremity : oval and tending towards the circular in transverse section. The 

 surface is smooth without tubercles or papillae, and the colour, in alcohol, is of a 

 uniform brownish grey, above and below, unrelieved by spots or other special 

 markings. 



