REPORT ON THE POLYZOA. 11 



Dr. JuUien' makes a genus Chaperia based on this character. He then says he does 

 not understand the object of these plates, and asks if they can be connected with the 

 ovicells. In his recent paper* he says that the plates are for the insertion of the muscles 

 on both faces. 



Of fossil forms Cellepora odontophora, Hagenow, Flustrellaria incrassata, d'Orbigny, 

 have somewhat similar plates, and probably when looked for they will be found in other 

 genera, but it does not seem that it is advisable to make a genus based merely on the 

 presence of these plates. 



There are two large distal rosette plates near the opercular wall of the zooecium, 

 and numerous communication points are spread over these plates. I consider that the 

 nature and position of these rosette plates is of the greatest value in systematic deter- 

 mination, but I do not find that they are always equally important generically, and, in 

 fact, in Membranipora spinosa they are small and numerous along the middle of the 

 wall, being exactly opposite in character to those of the present species, although, 

 according to JuUien, they must both be united under Chaperia on account of the 

 muscle plates. 



Foveolaria (?) elliptica, Busk (PI. III. fig. 19). 



Foveolaria elliptica, Busk, Zool. ChalL Exp., part xxx. p. 68, pi. xxiii. fig. 5. 



Perhaps this may have to be taken as the type of a genus Foveolaria, which would be 

 largely represented in the cretaceous. The greater part of the opesia is closed by the 

 operculum. There seems nothing to take hold of in the present definition of the genus 

 since the zoarial form is various ; then as to the aperture, it is also deeply imbedded in 

 many of the Membraniporidas ; and again the sessile avicularium of Foveolaria falcifera 

 is similar to that of Membranipora Jlemingii, Membranipora minax, &c., and the 

 operculum of Foveolaria tubigera and Foveolaria falcifera is of the ordinary Membrani- 

 poridan type. 



The avicularian mandible is similar to that of Membranipora tenuirostris, Hincks.' 



Membranipora falcifera, Busk. 



Foveolaria falcifera, Busk, Zool. Chall. Exp., part xxx. p. 69, pi. xv. fig. 6. 



The avicularian mandible is similar to that of Membranipora angulosa, and the small 

 chitinous piece at each side of the base also occurs here.'' In Foveolaria tubigera. Busk 

 {loc. cit., p. 68), the form of the zocecium and of the avicularian mandible is Membrani- 

 poridan (PL 11. figs. 29, 30). 



' Remarques sur quelques especes de Bryoz. Cheil., Bull. Soc. Zool. de France, torn. vi. p. 1 (sep.), 1881. 

 2 Bryozoaires, Mission du Cap Horn, Bull. Soc. Zool. de France, torn. ix. p. 61. 

 ' See Joum. Micr. Soc, ser. 2, vol. v., pi. xiv. fig. 41. 

 * See Joum. Micr. Soc., ser. 2, vol. v., pi. xiv. fig. 42. 



