ON THE RELATIONS OP EHABDOPLEITRA. 



581 



hicularia adunca of Grould is said to be a synonyjn of Necera 

 cochlearis, but is only known to me from its brief description in 

 the ' Otia ' ; its characters do not harmonize with those of L. 

 gravida. 



On the Relations of Wiahdopleura. 

 By Professor G. J. Allman, M.D., LL.D., F.E.S., President. 



[Read December 19, 1878.] 



Some years ago I founded this genus for a very remarkable Polyzoal 

 form dredged by Mr. G-wyn Jeffreys and the Eev. A. M. Norman 

 from a depth of 90 fathom.s in the Shetland seas *. My obser- 

 vations were made on specimens which had been preserved in 

 spirit ; and, as far as the condition of these would allow, 

 some interesting results were obtained. Gr. Ossian Sars, how- 

 ever, had nearly at the same time the good fortune to dredge, 

 from a depth of 120 fathoms, at Lofoten, off the Norwegian coast, 

 examples of another species of the same genus ; and he has been 

 thus enabled to make a very careful and complete examination of 

 the living animalt, and has in many important points rectified 

 and supplemented the observations made by myself on spirit 

 specimens. 



At first sight Bliabdopleura would seem to find its proper place 

 among the Phylactolaemata, to which it has the appearance of 

 being allied by its crescentic lophophore and by the homologue 

 of an epistome, if we so regard the remarkable shield-like organ 

 which in the adult animal is situated between the two orifices of 

 the alimentary canal. 



The crescentic lophophore of Bhahdopleura, however, is very 

 different from that of the hippocrepian or crescentic-disked Phy- 

 lactolaemata, from which it is widely separated by its interrupted 

 series of tentacles ; while I am by no means ready to admit that 

 the shield which constitutes so important a feature in this genus 

 is the homologue of an epistome. A comparison of the more 

 striking characters of Bhahdopleura with those of a typical poly- 



* Allman, on Rhahdopleura Normani. Quart. Journ. Micr. Sc., January 

 1869. 



t G. O. Sars, on Bhahdopleura mirahilis. 'The University Programme' for 

 1869. Christiania, 1872. Reprinted in Quart. Journ. Micr. Sc., January 

 1874. 



