398 Scientific Proceedings, Royal Duhlin Society. 



Halcampa from St. Yaast la Hougue, Manche (North France), 

 which he named Xanthiopus bilateraUs and X. mttatus, yen. et 

 sp. nov. Andres considers these as varieties of one species, which 

 he re-names Halcampa kefersteini, var. a. vittata, and var. j3. bilate- 

 raUs [l. c, p. 102). 



Keferstein's description is very meagre, and his figures imper- 

 fect; but there can be no doubt that the French species is distinct 

 from the Irish. 



EXPLANATION OF PLATE XYI. 



Halcampa andresii (sp. nov.). 



Fig. 1. — Side view of animal x 3 diam. 



,, 2. — Side view of disc and mouth, showing the tentacles in their 

 ordinary position x 4 diam. about. 



,, 3. — View of disc and tentacles from above x 4 diam. about. 



,, 4. — Side view of external aspect of tentacles x 4 diam. about. 



