ON THE ANGUILLULIDE. 143 
Pharyngeal cavily indistinct, with obscure indications of three slightly coloured 
pharyngeal plates. Œsophagus 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 erenated 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 two, 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. Ee- 
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. Cocxst', n. sp. (Plate XI. figs. 151-153.) 
Female, length 1", breadth 3347. ` 
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 set ; a few others scattered over anterior part of 
body. Integument hyaline, with an appearance of longitudinal markings 15005 apart. 
Pharyngeal cavity indistinct. (Esophagus about 1th of total length, embraced by ring 
at termination of anterior third; having three rows of pigment, varying from orange- 
eolour 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 15" from posterior extremity. Vulva slightly posterior 
to middle of body. Parietal glands in esophageal part of body very abundant. Ocelli 
two quite lateral, conical, bright-red pigment-masses. Excretory ventral gland open- 
ing by narrow duct, only 415" from anterior extremity, and terminating in a dilated 
extremity near the middle of cesophagus. 
Male, length +”, breadth 515”. | 
Anus 5” from posterior extremity. Spicules long, narrow, solitary ; length 435". 
Supplementary organ tubular, not very distinct, slightly eurved, giz” in length, and 
situated 4” above anus. 
Hab. About the roots of Corallines in tide-pools, Falmouth. 
2. P. AUBIDUM, n.sp. (Plate XI. figs. 154, 155. 
Female, length 1^, breadth 415". 
External Charucters.—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 cirelet 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- 
