ON THE ANGUILLULID^. 119 



circular markings of integument x^Vo" froni anterior extremity, by narrowed portions 

 T3s~s" ill length, with delicate vessels from xowo" to swo" broad. 



3Iale, not seen. 



Sab. Hemispherical tufts of moss (Tortula) on the roofs of old houses or walls, and 

 also from the yeUow lichen {Parmelia parietlna), Broadmoor, Berks. 



2. P. ciRRATTJS, n. sp. (Plate X. figs. 81, 82.) 



Female, length ^s", breadth -i-" 



'/ 



435 • 



JExternal Characters. — Body slender, tapering at both extremities, especially pos- 

 teriorly. Head rounded, provided with a circle of four very short cirri, about tTooo" 

 long. Integumental striae ^ooo^" apart, transverse. 



Pharyngeal cavity slightly dilated at first, then long and narrow, length being about 

 6^". Q^sophagiis less than ^th of total length. Intestinal cells not well marked, and 

 containing but few fat-particles. Aims xst" from posterior extremity. Vulva slightly 

 posterior to the middle of body. Duct of excretory gland opening opposite middle of 

 oesophagus. Lateral vessels commencing at x^o" fi'oiii anterior extremity. 



Male, not seen. 



Sab. About lower decaying leaves of Myriophyllimi verticillatuni, pond, Bagshot. 



3. P. TENUIS, n. sp. (Plate X. figs. 83, 84.) 

 Female, length ^3", breadth y^oo". 



External Characters. — Body white, slender, tapering very slightly anteriorly and pos- 

 teriorly. Head rounded, naked. Integumental strice transverse, almost imperceptible, 

 30000 apart. 



Fharyngeal cavity yi^" long. (Esophagus more than ^th of total length. Intestinal 

 cells containing but few light-coloured fat-particles. Anus -jyo" from posterior extre- 

 mity. Vulva at the middle of body. Excretory duct opening at xst" fi'om anterior 

 extremity. Lateral vessels commencing at circular markings 2-^0" from anterior ex- 

 tremity. 



Male, not seen. 



Sab. In transparent gelatinous matter, with Vorticella chlorostigma, from the shady 

 margin of a lake, Sandhurst. 



4. P. VELOX, n. sp. (Plate X. figs. 85, 86.) 

 Female, length ^", breadth voo"- 



External Characters. — Body white, tapering anteriorly and posteriorly, especially in 

 the latter direction. Head rounded, unarmed. Integumental striae transverse, ^-qooo " 

 apart. 



Fharyngeal cavity tc^To" long. Gilsophagns ^th of total length. Intestinal cells in- 

 distinctly marked, containing very few light-coloured particles. Anus -^^' from pos- 

 terior extremity. Vidva slightly posterior to the middle of body. Excretory duct 

 opening at yi^" from anterior extremity. Lateral vessels commencing at xgoq" from 

 anterior extremity. 



Male, not seen. 



Sab. From moss with T. Davaineii, Falmouth. 



