^" DC fx « V « »• n 



[work from the port ERIN BIOLOGICAL STATIG^.T , - 





NOTE on LUCEKNAKIANS occurring in the neigh- 

 bourhood of POET EEIN, ISLE OF MAN. 



By W. I. Beaumont, 



EMMANUEL COLLEGE, CAMBRIDGE. 



[Read May 12th, 1893.] 



Three species of this interesting group have been found 

 in the neighbourhood of Port Erin ; of these, one — Depas- 

 trum cyatliiforme — is fairly abundant, though apparently 

 local in its distribution, and the examination of a number 

 of specimens has enabled me to set at rest the divergent 

 views which have been held with regard to it. The other 

 two species have so far been found very sparingly : one is 

 a well known and widely distributed form, the other will, 

 I believe, prove to be a new species. The specimens were 

 collected and examined while I was working at the 

 L.M.B.C. Biological Station at Port Erin in the summer 

 of 1892 and again in the spring of 1893. 



Clark, in his Prodromus, (12)* divides the family Lu- 

 cernaridae (most of the members of which were originally 

 described under the generic name of Liicernaria) into two 

 sub-families : — 



1. Cleistocarpid.e, characterised by the development 

 of the gonads in " genital claustra " (mesogonial pouches 

 and gastrogenital pouches of other authors) which are di- 

 verticula of the central enteric space or stomach. To this 

 group belong Depastntm, CratewIojjJius, HaUcijathus. 

 ° 2. Eleutherocarpid.^, in which mesogonial pouches 

 or claustra are absent, the gonads being formed in the 

 subumbral or axial wall of the 4 perradial gastral pouches 



* The numbers in brackets refer to the List of Authorities at the end. 



