[ 81 



Calliobdella lophii, Van Beneden and Hesse. 



By 

 W. Harold Leigh-Sharpe. 



On May 12th, 1913, four specimens of the marine leech {Calliobdella 

 lophii) were taken by myself whilst working at the Marine Biological 

 Association Laboratory, Plymouth. The leeches were parasitic on the 

 skin of a large angler {Lophius 'piscatorius), just behind the gill covers 

 and in front of the pelvic fins, two on each side. The angler was caught 

 in JennyclifE Bay within a few hundred yards of the shore, about 3.15 

 p.m., half-ebb, and was taken in a small trawl only just large enough to 

 contain it ; shrimps were present in the same catch, but no fish. 



Calliobdella was previously unknown at Plymouth. The leech w^as 

 named by van Beneden and Hesse in 1863 from five specimens found in 

 March by Hesse at Brest.* Some of the external characters alone were 

 described by them. They omit to mention, however, that the genus 

 is characterised by its having six annuli to each body segment, a point 

 which it shares in common w^ith Ichthyobdella and Pontobdella, but 

 which separates it from other genera. They describe so accurately the 

 beautiful appearance of this leech that their own words suffice : — 



" An animal carrying a sucker at each extremity of the body, the 

 posterior very large and simple. The body divided into two distinct 

 regions, a neck region bare, and a region of the body properly so called, 

 this latter carrying laterally rounded tubercles on the segments or 

 cutaneous folds." 



" This species attains a length of five or six centimetres." (Two of 

 those captured at Plymouth were seven or eight without extreme exten- 

 sion.) " It lives on the angler (fishing-frog), Lophius piscatorius. The 

 body is elongated, slightly convex above, flattened below. The skin is 

 tough, with tubercles on the side, and divided into twenty-four segments, 

 of which ten or a dozen belong to the region of the neck, the others to 

 the body properly so called. The neck and the posterior sucker are 

 paler than the rest of the body ; the segments of the neck are covered 



* " Reclierches sur les Bdellodes on Hinidiiues, 1863." 



NEW SEllIES.— vol,. X. NO. 1. NOVEMKEU, 1913. F 



