ON THE ANGUILLULIDE. 99 
7. M. AMBIGUA, n.sp. (Plate IX. figs. 14, 15.) 
Male, length 47^, breadth 355 - 
External Characters.—Body narrowing gradually anteriorly, but tapering to a point 
abruptly behind orifice of genital tube. Sucker small, pointed. Head obtusely rounded, 
naked. Integument plain, having circular depressions on each side of head 755" in 
diameter. 
Œsophagus about ith of total length. Intestine having a kind of sphincter, with 
traces of a valvular apparatus at commencement ; otherwise covered with very large cells 
appearing in two rows, and containing rather light-coloured particles. Anus 335° from 
posterior extremity. Genital tube containing very large and distinct granular cells, 
opening rovo above anus. No spicules visible either there or at anal cleft. 
Female, not seen. | 
Hab. Marine, in sand from tide-pool, Falmouth. 
2. TRILOBUS!, Bastian. 
Anguillula, Leidy. 
Gex. CHAR. Body tapering considerably posteriorly. Caudal sucker small. Integument 
plain, or with longitudinal striæ; sete scarce. Pharyngeal cavity rather large, 
cup-shaped. Teeth none. Œsophagus cylindrical, having three lobes at termina- 
tion. Intestinal cells having pale-coloured fat-particles, more or less distinctly 
tessellated. Vulva about middle of body. Uterus bifid, segments symmetrical. 
Spicules solitary. Males having well-developed ventral suckers. Movements mode- 
rately active, frequently coiling when touched. 
1. T. GRACILIS, n.sp. (Plate IX. figs. 20-22.) 
Female, length 4", breadth 43337. | 
External Characters.—Body pale white, tapering slightly anteriorly, and gradually 
narrowing to a point posteriorly. Head bluntly rounded, provided with 4-6 stout, short 
sete. Integument rather thick, but very transparent, with longitudinal stri 10000 
apart. 
- Pharyngeal cavity distinct, cup-shaped. (Esophagus $th of total length, having three 
oval lobes at termination, each about 4” long. Intestinal cells containing almost 
colourléss fat-particles, not having distinct tessellation. Anus 10s from posterior ex- 
tremity. Vulva rather anterior to middle of body; whole of uterus and ovaries very 
readily seen. E 
Male much smaller than female, length 44", breadth 4157. Anus 135° from posterior 
extremity. Spicules solitary, segments narrow, nearly straight, about sts in length. 
Transverse striæ, as well as longitudinal, for some distance above the genital cleft of 
male; also in mid-ventral region a row of six large saeculi (suckers), in two sets of three, 
each sacculus about 3 500 deep. 
Hab. About the roots of Ruppia maritima from brackish water, Falmouth. 
À rpeis, three, me Aoßos, a lobe. Ud 
