151 



ginal portion, and most developed in C. aurita (fig. 4 a). In C. minax its extent 

 is similar to that in C. imbellis but is often indistinct, as it is not always 

 stiarply defined. In all of them there is a cryptocyst, the development of which 

 is however not only different within the different species, but also varying ac- 

 cording to locality and age of zooecia. Its development is slightest in C. craticula 

 and C. lineata, in which it is only a narrow marginal portion inside the spines, 

 greater in C. Dumerili and C. aurita, and still greater in C. Flemingi, C. trifolium, 

 C. imbellis and C. minax. The last four species are evidently most closely allied. 

 In the last-named species we find a strongly developed avicularium with an 

 unusually high chamber (» mounted on a pedicel* Norman'); but in this diffe- 

 rence I cannot find sufficient reason for setting up a new genus. 



A later examination of some good colonies of Doryporella spathulifera has corro- 

 borated my view as to the systematic position of this species which I must refer 

 to the present genus. As I am later to give a full description of this species in a 

 work on the Ingolf Bryozoa I may here just mention a few points of its structure. 

 The so-called median pore is the aperture of an avicularium of the same form 

 as those found in the distal part of the zooecium and corresponding to that found 

 proximally to the aperture in C. Flemingi, C. minax and C. lineata, and in the 

 last species there may also as in C. spathulifera be found a spine distally to the 

 avicularium. There are 6 rosette-plates in the proximal half of the zooecium. 



In old colonies of C. Flemingi, C. minax and C. spathulifera there may be 

 found a compound operculum, the opercular valve and the membrane filling 

 the rest of the aperture being fused together into a separable chitinous lamina. 



Megapora Hincks. 

 The zooecia have a strongly developed, partially depressed cryptocyst and 

 an aperture surrounded by spines and with a well-developed vestibular arch. 

 A compound operculum in which the valvular part and the accessory part are 

 connected by a joint. A few few-pored pore-chambers. No avicularia. Hyper- 

 stomial ocecia whose ectoocecium is calcified with the exception of a frontal 

 triangular membranous part covering a corresponding very prominent granular 

 part of the endoooecium. The only species hitherto -known are M. ringens, and 

 M. hyalina Waters 2. They are undoubtedly closely related to the Flemingi-group 

 within the genus Callopora. 



1 83, p. 597. ^ 115, p. 39, 



