ADDITIONAL L.M.B.C. TtfKBELLAKlA. 173 



colour distribution as in v. Graff, Monographie, Tab. xxii., 

 %• 6,/. 



Vorticeros auriculatum (0. F. Miiller). 



Three specimens among seaweeds, opposite the biologi- 

 cal station. 



An individual 1'8 mm. long was taken in the tow-net 

 by Mr. A. E. Jackson, at sunset on the 26th April in 

 Port Erin Bay. 



Cylindrostoma quadrioculatum (Leuckart). 



A few specimens among Cladophora, collected in shallow 



jock pools near high-water mark, beside the biological 



station. This species seems particularly sensitive to light, 



and only appeared at the surface of the vessels, in which 



I put the Cladophora, after dark. 



Family Monotid^. 



Monotus lineatus (0. F. Miiller). 



Port Erin and Port St. Mary, very common among 

 seaweeds collected between tidemarks. 



In the great majority of the specimens that I examined 

 the eye spot had the form of an irregular semilunar patch 

 of pigment, such as is figured by Boeck (7), PI. F., figs. 

 2, 6 and 9, or by von Graff (6), Tab. xx., fig. 18. One 

 individual, however, taken at Port St. Mary presented 

 such an extreme reduction of the "eye" that I have 

 figured it (PL V., fig. 2). Here it is merely represented 

 by a faint row of granules, forming a semicircle in front 

 of the otolith. 



Monotus fuscus (Oersted). 



Common in tide-pools, and among tidal refuse, at Port 

 Erin. Also found at Port St. Mary, but nowhere was it 

 quite so numerous as M. lineatus. 



