BRYOZÛA 35 



as in Cellaria, and in a spécimen sent to me as Rhagasostoma elegans d'Orb. (') from Faxoe 

 there are similar teeth, and the upper teeth \ve must look upon as the équivalent of the lamella 

 in the Cellepora vaginata of Hagenow, for which Canu has proposed the genus Hagenowilla. 

 In R. elegans the upper teeth are seen to be the ends of a lamella, the same shape though 

 smaller and less developed than that in H. vaginata. A shelf is known in many gênera, and 

 Levixsex ( 2 ) has called attention to its importance. 



There seems good reason for thinking that the cretaceous Rhagasostoma as given by 

 Canu are closely allied to Cellaria. The lower lip turns up as in Cellaria and the opening 

 has been closed by the operculum, though no doubt there has been a covering membrane 

 as in Cellaria. In Rhagasostoma Argus d'Orb. and its allies there is no cross bar to the avicu- 

 larium, resembling in this respect avicularia of some Cellaria, as for example C. Dennanti Mac G. 

 Again in Onychocella angulosa Reuss, there is no distinct bar, in fact sometimes no trace of 

 any protubérance is seen ; while in others two ridges indicate the bar, and in the cretaceous 

 fossils of this group, there are numerous cases of onychocellaires without a bar, so that from 

 analogy we may say the base of the mandible was across the middle of the opening, and 

 was attached to a membrane covering the proximal end of this vicarious avicularium. Of the 

 cretaceous fossil Bryozoa a very large proportion are related to Onychocella. In the Melicerititidœ 

 there are also vicarious avicularia, as shown in my paper already referred to, but Levixsex (') 

 says- that the avicularia do not quite agrée with those occurring in Cheilostomata. The main 

 différence according to Canu is that there is no membranous area (submandibular area) 

 proximal to the mandible, and it is true that there seems to be a différence, but in M . toyana 

 Waters (see fig. 2, loc. cit.) the submandibular portion is depressed, and no doubt this has 

 been covered by a membrane connected with the mandible. The lower part of the avicu- 

 larium of M. semiclausa d'Orb. (fig. 1, loc. cit.) is similar to the lower part of the zoœcium. 

 While it is of interest to find the submandibular part of the avicularium is calcified it seems 

 perhaps too much to sa)' that they are of a différent type, and I cannot agrée with Levinsen, 

 that the slight différences furnish a reason for placing M eliceritites with the Cyclostomata. 



Since writing the above I hâve seen in the Muséum d'histoire naturelle de Paris, among 

 the Julliex material, a spécimen from the Bancs des Aiguilles, South Africa, which is closely 

 allied to, if not identical with the Macropora cribrilifera Maplestone, fossil from Mitchell River, 

 Victoria, and the large vicarious avicularia are without any submandibular area, thus entirely 

 corresponding with the avicularia of Melicerititidœ. The vicarious avicularium has the same 

 position and shape as those of Lepralia claviculata Hincks, but the mandible is spatulate, 

 and there is no submandibular area or mark. Macropora to my mind is a synonym of 

 Monoporella, and it seems nearest related to Lepralia, having a straight edge to the proximal 

 wall of the oral aperture. 



Gregory, Canu, and Levinsen would still retain Melicerititidœ under Cyclostomata 



(1) The zoœcia at the border are similar to those on the front surface of the zoarium, and therefore I am 

 not quite sure as to the correctness of the détermination. 



(2) Studies on Bryozoa. (Vidensk. 'Medd. fra den Naturh. Foren i Kjôbenhavn, 1902, p. 19.) I hâve referred to 

 such a shelf and teeth in my paper on Bryozoa from Bairnsdale, as occurring in the fossil Ciihrilina monoceros. 

 {Quart. Joion. Geol. Soc, vol. XXXVIII, p. 507.) 



(3) Loc. cit., p. 29. 



