190 F. W. GAMBLE, B.SC. 



Habitat. — Among stones and seaweed at the base of the littoral 

 zone, Plymouth, Port Erin, Isle of Man (F. W. G.) ; Millport (v. Graff). 



Distribution. — Naples, Trieste, Roscoff (v. Graff) ; Denmark 

 (Oersted, 21) ; in colonies among Laminaria and Fucus, a few feet 

 below the surface, Bergen (Jensen). 



4. Aphanostoma elegans, Jensen. 



Length *75 mm. Body colourless, with a lobate dark green spot in 

 the centre due to coloured parenchymatous vacuoles. Form broadly 

 rounded in front, tapering gently posteriorily. Eyes absent. The 

 male genital aperture lies a short distance in front of the hinder end ; 

 the female pore close behind the green spot. According to Jensen the 

 spermatozoa are long, filiform, thicker and spirally twisted anteriorly. 



Habitat. — Among Ulva, between tide-marks, Plymouth (F. W. G.). 



Distribution. — Alvoerstrom and Bergen (Jensen, 49). 



Jensen's description reads, " Corpus utraque extremitate rotun datum 

 in anteriore parte latius, retrorsum sensim angustius." My specimen 

 was certainly during active motion broader in front than behind, 

 approaching Jensen's figure of A. rhomboides (49, pi. i, fig. 1). 



Aphanostoma is a distinctly northern genus. The coast of Denmark 

 and the western shores of Norway and Greenland have furnished the 

 bulk of the existing records. The presence of A. elegans at Plymouth 

 suggests that further search will reveal localities for the remaining 

 species on our coasts. 



Genus 4. Convoluta, Oersted (16), 1844. 



Aphanostomidce with a broad, flat body, the margins of which are in some 

 forms capable of being flexed ventrally. Spermotheca with a 

 chitinous mouth-piece. 



5. Convoluta saliens, v. Graff, 1891. 



1882. Cyrtomorpha saliens, v. Graff, (53). 

 Length 1 mm. Body elliptical, the dorsal surface convex, ventral 

 surface flat. Colour is absent except in the centre, where it is due to 

 brown food -particles among the parenchyma. Locomotion is effected 



