444 F. W. GAMBLE. 



gustius." My specimen was certaiuly during active motion 

 broader in front than behind, approaching Jensen's figure of 

 A. rhomboides (49, pi. i, fig. 1). 



Aphanostoraa is a distinctly northern genus. The coast 

 of Denmark and the western shores of Norway and Green- 

 land have furnished the bulk of the existing records. The 

 presence of A. elegans at Plymouth suggests tliat further 

 search will reveal localities for the remaining species on our 

 coasts. 



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



Aphanostomidse 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. Cyktomorpha 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 thus: — From the anterior end backwards 

 for one-third of its length the margins of the body are capable 

 of being gradually extended outwards, so that the greatest 

 width of these animals when in motion is a short distance in 

 front of the centre of the body. These lappets are then flapped 

 inwards and downwards, the animal at the following instant 

 leaping forward. When, however, contraction occurs, it is no 

 longer possible to define the lappets. The anterior end is at a 

 much lower level than the rest of the dorsal surface. As the 

 change of level is abrupt the front end appears snout-like, 

 especially when seen from the side. This snout is moved from 

 side to side in a sensitive manner. Short cilia and slightly 

 irregular rhabdites are present in the epidermis, and 



