86 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



SECTION 1. MEMBRANIPORAE WITHOUT OVICELL. 

 Genus CONOPEUM Norman, 1903. 



1903. ffiiio/icum NORMAN, Natural History ..I' Fast Finmark, Annals Magazine Natural His- 

 tory, scr. 7, vol. 11. 11. 5xi; (1S4S. (iray. List British Animals British Museum. < Vn- 

 troniae. pp. 108. 146). 



No ovicell, no dietellae. no avicularia. The margins of the mural rim are wholly 

 granulated. A distal, multiporous septula: two or three lateral septulae. Tri- 

 angular, interopesial hollows having special walls. 



fr< of>/pe. M eiribranipora Incroi.i'ii Authors. 



[t'n iii/< . Cenomanian-Recent. 



The granulations of the mural rim are often very fine and attenuated on the 

 fossil forms. In these also the distal septulae often unite into a very large pore. 



- ca 



D*85 



FIG. 25. Genus Cniioin'inn Norman. 1903. 



A-D. ('ijiioiieuin liti-mi.rii Busk, 1852. A. /unecia, X 25. B. Zooecia, X 25, with intero- 

 pesial cavity ( /. c. ) ; operculum (op), anil opesium (<>t>ii. C. Dorsal surface, X 25. showing a 

 pair of transparent circles I/. .v. = lueul spots of Norman i, irregular projections (7/f) on the 

 lateral wall, and a pair of projections l. /i. t on rlp> ilist;il wall opposite those on the next 

 zooeci uni. D. Operculum, X 85, with chitinor.s arch (en] and membranous extension (en). 

 i A. B after Hincks. ixsu. and C, I> after Waters. 1898.) 



The hollows of the surface are not interzooecial, as Levinsen has described them. 

 but are only interopesial: they are not deep and are situated between the mural 

 rims; rarely they contain an avicularium; their purpose is unknown. In living 

 specimen^ Waters has described two lucid spots on the dorsal side. These are 

 replaced on the fossils by two hollow impressions in the dorsal olocyst. We are 

 ignorant of their use, for they have no connection with the operculum. 



The type of this genus is very common on the coasts of France and England, 

 and Osburn has noted its occurrence in American waters. However, no naturalist 

 has made a study of its embryology and anatomy. 



The known species of this genus, in addition to the genotype, are: 



a in (Membranipora) l/rni-nnli ('ami. 1011, Rocanean of Argentina. 

 i (Membranipora) <irl><n<<i ('ami. 1011. Rocanean of Argentina. 

 Con/>i>iinn (Membranipora) luni/nm, ('ami. 1911, Rocanean of Argentina. 



(Membranipora ) >ini/>?< stont ! ('ami. lull. Rocanean of Argentina. 



