ON THE ANGUILLULID^. 137 



very dark in colour, hollow, 1x3" long; accessory piece wanting. Uxcretory ventral 

 gland not recognized. 



Female, not seen. 



Hab. Marine surface-mud of estuary, Falmouth. 



5. O. ALBiBus, n. sp. (Plate XI. figs. 141, 142.) 

 Female, length ^', breadth Yg-e". 



External Characters. — Body elongated, whitish in colour, tapering anteriorly, but 

 more towards posterior extremity ; tei'minating in a moderate-sized sucker. Head trun- 

 cate, provided with a circlet of four short, stout setae, and a few smaller ones scattered 

 over anterior part of body. Integument having longitudinal markings. 



Pharyngeal cavity broadly ovate, -g-g^" long. (Esophagus short, about xoth of total 

 length ; enlarging slightly posteriorly ; no ring seen. Intestine moderately well covered 

 with rather light-coloured hepatic particles tessellated in arrangement. Anus yoo" from 

 posterior extremity. Vulca considerably behind middle of body, ^s" from posterior 

 extremity. Uterus unsymmetrical. Ova very large, in single file, occupying the whole 

 width of the body, and somewhat flattened against its parietes. Excretory ventral gland 

 opening far forward, at 2^" from anterior extremity. 



Male, not seen. 



lEab. Amongst small stones and sand in tide-pools, Falmouth. 



6. 0. viRiDis, n. sp. (Plate XI. figs. 137, 138.) 

 Female, length ^", breadth 3-3^3". 



External Characters. — Body of a light-greenish hue, tapering very slightly forwards,, 

 but somewhat abruptly behind anus, where it terminates with a pretty distinct sucker 

 and sucker-tubes. Head truncated, provided with a circlet of 4-6 setae; a few other 

 smaller ones scattered over anterior part of body. Integument having longitudinal 

 markings. 



Pharyngeal cavity broad anteriorly, ^^" 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 ocellus. Intestine well 

 covered with hepatic particles having a distinctly tessellated arrangement. Anus ^-§-5" 

 from posterior extremity. Vulva prominent, considerably behind middle of body, jj" 

 from posterior extremity. Uterus unsymmetrical. 



Male, not seen. 



Hab. Small filamentous green weed from tide-pool, Falmouth. 



7. O. ATTENUATUS, Dujardin. (Plate XI. figs. 184-136.) 

 Enoplus attenuatus, Diesing, Syst. Helminth, ii. p. 125. 



Female, length xq", breadth tst "• 



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 setse. Integument having longitudinal markings. 



Pharyngeal cavity elongated, ee?" in length. (Esophagus about \ila. of total length, 



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