ON THE ANGUILLULIDiE. 143 



Pharyngeal cavity indistinct, with obscure indications of three slightly coloured 

 pharyngeal plates. (Esophagus not distinctly muscular, widening posteriorly, sur- 

 rounded by a ring, and in its latter half having circular contractions of its sheath 

 at intervals, giving its border a regular crenated appearance ; three longitudinal 

 rows of orange- or other coloured pigment-granules more or less marked along 

 its whole extent. Intestine covered with somewhat olive-coloured fat-particles, 

 having a tessellated arrangement. Vulva about middle of body. Uterus bifid; 

 segments symmetrical. Spicules t^o, long and narrow ; accessory piece wanting. 

 Supplemental organ small, obliquely situated, tubular. Ocelli two, large, conical, 

 bright red, situated laterally. Parietal glands, on muscles, well developed. Ex- 

 cretory ventral gland consisting of a short tube, with a blind dilated extremity, 

 and opening by an abruptly narrowed duct near anterior extremity. Lateral canals 

 distinctly cellular. ' 



Movements active. 



1. P. CocKSi', n. sp. (Plate XI. figs. 151-153.) 

 Female, length \", breadth xki". 



■ External Characters. — Body tapering very gradually forwards, but narrowing quickly 

 to a point behind, where it terminates in a well-developed sucker. Head narrow, 

 rounded, provided with a circlet of 6-8 setae ; a few others scattered over anterior part of 

 body. Integument hyaline, with an appearance of longitudinal markings ttooo" apart. 



Pharyngeal cavity indistinct. (Esophagus about |th of total length, embraced by ring 

 at termination of anterior third ; having three rows of pigment, varying from orange- 

 colour to olive-green, along its whole length ; constrictions of posterior half at regular 

 intervals, giving a crenated appearance to borders. Intestine well covered with a tessel- 

 lation of hepatic particles. Anus y^" from posterior extremity. Vulva slightly posterior 

 to middle of body. Parietal glands in oesophageal part of body very abundant. Ocelli 

 two quite lateral, conical, bright-red pigment-masses. Excretory ventral gland open- 

 ing by narrow duct, only 2^" from anterior extremity, and terminating in a dilated 

 extremity near the middle of oesophagus. 



Male, length \", breadth -a^f". 



Anus "2^" from posterior extremity. Spicules long, narrow, solitary ; length yW- 

 Supplementary organ tubular, not very distinct, slightly curved, -g^" in length, and 

 situated ^" above anus. 



Sab. About the roots of Corallines in tide-pools, Falmouth. 



2. P. ALBiDUM, n. sp. (Plate XI. figs. 154, 155. 

 Female, length \", breadth ^^". 



External Characters. — Body white, tapering gradually at extremities, not suddenly at 

 posterior, as in last; terminating in distinct sucker, with which are connected three 

 sucker-tubes. Head narrowed, rounded, having a circlet of 6-8 spreading cirri. In- 

 tegument very hyaline and transparent. 



' Named after my dear and valued friend, W. P. Cocks, Esq., to whom science is much indebted for his researches 

 into the marine zoology of Falmouth, resulting as they did in the discovery of so many new species of animals. 



