BOYCOTT : GENITALIA OF THEBA CANTIANA. I25 



the same time and place. Closer examination suggested that this 

 appearance was due to invagination or, more properly perhaps, 

 intussusception, the process being more advanced, or less regressed, 

 in D than in C. Transverse sections confirmed this view and 

 showed clearly that the organs were folded up. F gives diagram- 

 matically a section across D about the level of the distal flexure in 

 figure D ; the epithelial lining is shown in heavy black, the muscular 

 wall streaked. The first space from the periphery is the lumen of 

 the organ, the second the body cavity in which the organ lies, and 

 the third the lumen of the organ more towards its tip. C shows this 

 process of tucking in partly done. E shows sections of the normal 

 organ. The magnification of A, B, C and D is given in A ; the line 

 under F refers to E and F. 



These facts suggest that the " doubtful organ " may be everted and 

 act as an excitatory organ or egersidium. It might perhaps be called 

 an "atrial flagellum." 



PROCEEDINGS OF THE 

 CONCHOLOGICAL SOCIETY OF GREAT BRITAIN & IRELAND. 



452nd Meeting, held at the Manchester Museum, May loth, 1916, 



The President in ihe chair. 



Additions to the Library announced and thanks voted : 



" Manual of Conchology," part 92, by H. A. Pilsbry (front the author) ; and 

 the usual periodicals received in exchange. 



Additions to the Autograph Letter Collection announced and thanks voted : 

 Messrs. Suter, Shaw, Nobre, Connolly, Farquhar, Barnard, Cregoe, Rolle, Dall, 

 Bavay, and J. J. Walker. Donor : J. Ponsonby-Fane. 



Donations to the Cabinet (per the Hon. Recorder) : 



From Capt. W. J. Farrer, Messrs. Chas. Upton, E. D. Marquand, and Cecil P. 

 Hurst. 



New Member Elected. 

 Giuseppe Despott. 



Candidate Proposed for Membership. 



Professor M. Doello Jurado, Museu Nacional, Peru 208, Buenos Ayres. 



Papers Read. 



"Note on Coelocentrum gigas von Mts.," by G. C. Spence. 

 " Notes on Hilix pisana Miill., and its Occurrence at Porthcawl, Glamorgan," 

 by J. Davy Dean. 



"New Records for Pembrokeshire," by J. Davy Dean. 



