504 F. W. GAMBLE. 



gut extending to posterior extremity. Body 

 around the pharynx and main-gut frequently 

 thickened. Uterine glands corresponding to 

 the number of the secondary gut-branches. Ten- 

 tacles well developed, pointed, moveable. Two 

 small cephalic groups of eyes. Brightly coloured 

 forms. 



65. Prosthecer^us vittatus (Montagu). 



1815, Planakia vittata, Montagu (7). 

 1823. „ „ Fleming (8). 



1840. „ „ Tliompson (15). 



1845. „ „ Johnston (20). 



1846. „ „ Thompson (22). 

 1857. M „ Harvey (31). 

 1865. EuRYLEPTA VITTATA, Johnston (38). 

 1884. Pkosthecek^us vittatus, Lang (54). 

 1886. „ „ Koehler (55). 



Length 3'7 — 5 cm. Body elliptical, tapering towards 

 both extremities. The tentacles are lamellar, broad at their 

 bases, which enclose between them the extreme anterior tip 

 of the body in such a way as to separate it off slightly from 

 the margin. The general colour is yellow, the margins white. 

 The median ridge is distinguished by a black line. Right and 

 left of this a number of black lines (increasing in number and 

 distinctness with the age of the individual) run from the brain 

 towards the hinder end. Those near the median plane are 

 almost straight ; the peripheral run parallel with the body 

 margin. The mouth lies behind the brain. The main -gut 

 is long, and gives off large numbers of secondary gut branches, 

 which anastomose freely. Eyes occur over the brain as a pair 

 of small, clearly defined cephalic groups, on the anterior 

 margin and in the tentacles. The sucker is subceutral. 

 Halfway between it and the mouth is the male aperture, and 

 behind this the female genital pore. The vesicula semi- 

 nalis and granule- gland open independently iuto the 

 ductus ejaculatorius. 



