ON THE ANGUILLULIDA. 137 
very dark in colour, hollow, 143” long; accessory piece wanting. Excretory ventral 
gland not recognized. 
Female, not seen. 
Hab. Marine surface-mud of estuary, Falmouth. 
5. O. ALBIDUS, n. sp. (Plate XI. figs. 141, 142.) 
Female, length +”, breadth 47 - 
External Characters.—Body elongated, whitish in colour, tapering anteriorly, but 
more towards posterior extremity; terminating in a moderate-sized sucker. Head trun- 
cate, provided with a circlet of four short, stout setæ, and a few smaller ones scattered 
over anterior part of body. Integument having longitudinal markings. 
Pharyngeal cavity broadly ovate, 545" long. (Esophagus short, about „sth of total 
length ; enlarging slightly posteriorly ; no ring seen. Intestine moderately well covered 
with rather light-coloured hepatic particles tessellated in arrangement. Anus 15” from 
posterior extremity. Vulva considerably behind middle of body, 4l" from posterior 
extremity. Uterus unsymmetrical. Ova very large, in single file, occupying the whole 
width of the body, and somewhat flattened against its parietes. Exeretory ventral gland 
opening far forward, at 545” from anterior extremity. 
Male, not seen. 
Hab. Amongst small stones and sand in tide-pools, Falmouth. 
6. O. VIRIDIS, n. sp. (Plate XI. figs. 137, 138.) 
Female, length +”, breadth 414". | 
External Characters.—Body of a light-greenish hue, tapering very slightly forwards, 
but somewhat abruptly behind anus, where it terminates with a pretty distinet sucker 
and sucker-tubes. Head truncated, provided with a cirelet of 4—6 setæ; a few other 
smaller ones scattered over anterior part of body. Integument having longitudinal 
markings. 
Pharyngeal cavity broad anteriorly, 343" long. (Esophagus about $th of total length, 
uniform in size, embraced obliquely by ring near its middle; having a collection of 
pigment immediately behind pharynx somewhat resembling an ocellws. Intestine well 
covered with hepatic particles having a distinctly tessellated arrangement. Anus 545" 
from posterior extremity. Vulva prominent, considerably behind middle of body, 37” 
from posterior extremity. Uterus unsymmetrical. 
Male, not seen. 
Hab. Small filamentous green weed from tide-pool, Falmouth. 
i. 0. ATTENUATUS, Dujardin. (Plate XI. figs. 134-136.) 
Enoplus attenuatus, Diesing, Syst. Helminth. ii. p. 125. 
Female, length 455", breadth 45”. 
External Characters.—Body long and slender, tapering very slightly at extremities, 
though most at posterior, which is somewhat blunt, and terminated by a well-marked 
Sucker, with which are connected sucker-tubes. Head bluntly rounded, provided with a 
circlet of 6-8 setze, Integument having longitudinal markings. 
 Pharyngeal cavity elongated, gt,” in length. Œsophagus about sth of total length, 
VOL. xxv, T 
