W. A. Harding 
139 
Diagnosis. Body vermiform in young individuals, claviform in 
adults, blackish yellow or olive, spotted with white. Anterior region 
with four pairs of lateral non-pulsating tubercles. Clitellmn retracted 
and composed of three large rings followed by six small rings; the 
male orifice opens between the first and second, and the female orifice 
between the fourth and fifth, of these small rings. 
Each of the first twelve somites of the posterior region of the body 
bears a pair of lateral pulsating vesicles which, in diastole, arch up the 
skin of the first two rings. Eight small rings separate the last pair of 
vesicles from the campanuliform posterior sucker; the anus lies between 
the antepenultimate ring and the last ring but one. Length 50 mm. 
in extension ; 20—30 mm. in contraction. 
[Note. The diagnosis of the genus Trachelobdella and the descrip¬ 
tion of T. lubrica are condensed from those given by R. Blanchard 
(1894 b). The synonymy of this species is chiefly taken from the same 
source.] 
Hosts. This species is found on the gill-covers, in the pharynx and 
rarely on the ventral fins of various fish, generally of small size, such as 
Scorpaena porous, Sargus annularis, Corvina umbrina, Caranx trctchurus, 
Uranoscopus scaber, Lophius piscatorius, Blennius pholis, Gobius niger, 
Goris giofredi, Solea vulgaris (Apathy). 
Genus: Piscicola, de Blainville, 1818. 
Synonymy: 
Piscicola, cle Blainville, in Lamarck, 1818. Haemocharis, Savigny, 1822, p. 106 (not 
Haemocharis, Filippi, 1837). Ichthyobdella, de Blainville, 1827. 
Fresh-water leeches, ectoparasitic on fish. Body very long, smooth 
and cylindrical, the posterior region with paired, lateral, pulsating 
vesicles. Suckers large and excentrically attached, the posterior and 
largest with a paramarginal series of oculiform spots. Four eyes upon 
the anterior sucker, the first pair linear and oblique. Complete somite 
formed of fourteen rings. * 
