MEDITEEEANEAN AND NEW-ZEALAND EETEPOE^. 



2C1 



Eetepoea Couchii, JLinchs. 



Iroin Eapallo there are specimens witli large fenestrse, as in 

 Naples specimens, and there are others witli very small meshes ; 

 and, in fact, this species shows us very clearly that too much 

 importance must not be attached to size and shape of the meshes. 

 Usually the fenestras are about 2 mm. long, 0"8-l mm. wide, and 

 the branches are 0'4 mm. wide ; whereas the smaller form from 

 Eapallo has the meshes 0*8 mm. long, 0"4-0"6 mm. wide, and one 

 from Roscoff, sent by Joliet as " cellulosa^'' has the meshes only 

 06 mm. long and 02 mm. wide, with the branches 0*4 mm. wide. 



Although there may be a considerable range in the size of the 

 fenestras, yet there is in most a typical form which should be 

 described, and therefore the following table, prepared from 

 specimens in my collection, may be useful for comparison : — 



Eetepoea-cellulosa Group, 



E. cellulosa, L. ; Naples 



do. Zoagli ... 



do. N. Cape... 



complanata, Waters 



mediterranea, Smitt 



aporosa, Waters 



Couchii, H. ; typical 



do. 

 do. 

 do. 



Eoscoff..... 



Eapallo . . 



var. biavicu 



lata, W. 



do. .. 



Fenestrse. 



do. 



Beaniana, King 



producta, B 



Hssa, MacG 



atlantica, B. ; Chall 



jacksouiensis, B 



porcellana, MacG. .. 



Eetbpora-monilifera Group. 



E. umbonata, Mac G 



munita, MacG 



columnifera, B 



victoriensis, B 



contortuplicata, B 



columnifera, B 



tubulata, B 



formosa, MacG 



Long. 



millim. 

 1-0 

 0-9 

 12 

 20 

 1-6 

 1-8 

 20 

 0-6 

 0-8 



2-0 

 1-2 

 10 

 3-6 

 1-2 

 1-4 

 1-4 

 1-8 



1-0 

 1-0 



0-8 

 0-6 

 10 

 0-8 

 0-6 

 0-8 



Wide. 



millim. 



0-6 



0-4 



0-4 



0-8 



0-8 



0-8 



0-8 



0-2 

 0-4-0-6 



0-8 

 0-4 

 0-6 

 0-6 

 0-3 

 0-6 

 0-6 

 0-6 



0-6 

 0-4r-0-6 

 07 

 0-4 

 0-6 

 0-7 

 0-4 

 0-4 



Pro- 

 portion. 



Branches. 



1-0-6 

 1-0-4 

 1-0-3 

 1-0-4 

 1-0-5 

 1-0-4 

 1-0-4 

 1-3 

 1-0-4 to 0-5 



1-0-4 



1-0-3 



1-0-6 



1-0-17 



1-0-25 



1-0-4 



1-0-4 



1-0-3 



1-0-6 

 l-0-4to0-6 

 1-0-9 

 1-0-6 

 1-0-6 

 1-0-9 

 1-0-6 

 1-0-5 



Wide. 



millim. 

 0-6 

 0-5 

 0-6 

 0-6 

 0-8 

 0-5 

 0-4 

 0-4 

 0-6 



0-4 

 0-6 

 0-6 

 1-2-1-4 

 0-6 

 0-6 

 0-6 

 1-2 



1-2 



0-8 

 0-5 

 0-8 

 0-6 

 0-5 

 0-4-0-6 

 0-6 



