242 P. W. GAMBLE, B.SC. 



Genus 30. — ProstheceRjEUS, Schmarda.* 

 Body smooth, delicate. Pharynx bell-shaped. Main-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. Tentacles well developed, pointed, 

 moveable. Two small cephalic groups of eyes. Brightly coloured 

 forms. 



65. PROSTHEOER^US VITTATUS (Montagu). 



1815. 



Plan aria 



VITTATA, Montagu (7). 



1823. 





,, 



Fleming (8). 



1840. 





)5 



Thompson (15). 



1845. 





3) 



Johnston (20). 



1846. 





J> 



Thompson (22). 



1857. 





5) 



Harvey (31). 



1865. 



Eurylepta VITTATA, Johnston (38). 



1884. 



Prosthecer^eus 



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 subcentral. 

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

 this the female genital pore. The vesicula seminalis and granule -gland 

 open independently into the ductus ejaculatorius. 



Habitat — Estuary of Kingsbridge, S. Devon (Montagu) ; coast of 

 Scotland (Fleming) ; Strangford Lough (W. Thompson) ; between 

 tide-marks at Roundstone, Connemara (W. Thompson) ; British coast 



* Schmarda,L. K., " Neue wirbellose Thiere, beobachtet und gesammelt auf 

 einer Reise urn die Erde, 1853—1858,' Bd., i, 1859. 



