NORTH AMERICAN EARLY TERTIARY BRYOZOA. 327 



angular rimule. The gonoecia are larger than the other zooecia and have a dif- 

 ferent form ; they never contain a polypide ; they contain an ovary and an incuba- 

 tion cavity which is a sort of endozooecial ovicell. There are male zooecia smaller 

 than the normal zooecia. 



Genotype. Hippothoa divaricata Lamouroux. 1821. 



Range. Lutetian-Recent. 



Historical. Lamouroux created this genus for all uniserial incrusting zoaria 

 of Ascophora bearing generally zooecia very much narrowed behind. The genus 

 was based entirely on zoarial features. By juggling the definition, it was trans- 

 formed in 1880 by Hincks into a genus based on zooecial features, and included 

 only those species in which the aperture bears a small rimule. It is evident that 

 we may observe hippothoiform zooecia provided with a different hydrostatic system 

 and consequently with an aperture of a different form. 1 Furthermore, Jullien in 

 1886 dismembered the old genus Hippothoa and applied the name of Diazeuxia 

 to the group of the species with a small rimule. Waters, in 1900, and Levinsen, in 

 1909, preserved the definition of Hincks. 



HIPPOTHOA (?) CONJUNCTA, new species. 

 Plate 7, figs. 15, 16. 



This species is certainly not a Hippothoa, for its aperture is elliptical and 

 without a small rimule. The four specimens discovered are too few for the study 

 of characters sufficient to establish a new genus, especially as they bear no ovicell. 



The zooecia are provided with a caudal portion, which is very long, thin, and 

 stoloniform. When such a portion encounters another they join together and the 

 gemmation of a branch is arrested. This is a peculiarity which we have never 

 observed in Hippothoa. 



Occurrence. Midwayan (Clayton limestone) : Luverne, Crenshaw County, 

 Alabama (rare). 



Cotypes.Cnt. No. 63823, U.S.N.M. 



HIPPOTHOA ? species undetermined. 



Plate 44, fig. 5. 



The specimen collected is very mediocre and bears only a single zooecium 

 intact. In the form of its aperture it is neither Hippothoa nor Dacryopora. We 

 have mentioned it simply to call attention to the occurrence. 



Occurrence. Upper Jacksonian (Ocala limestone) : Chipola River, east of 

 Marianna. Jackson County, Florida (rare). 



Genus TRYPOSTEGA Levinsen, 1909. 



Zonlogifal bibliography. 1909. LEVINSEN, Morphological and systematic studies on the Cheilo- 

 stomatous Bryozoa, p. 280, pi. 19, fig. 1 ; pi. 23, fig. 13. 1913. WATERS, The Marine Fanr.a of 

 British East Africa and Zanzibar, Proceedings Zoological Society, London, p. 507. 



'This is notably so in the case of the genus Dacryopora Lang, 1914 (Geological Magazine, ser 6, vol. 1, 

 p. 440, pi. 34, figs. 4 and 5). 



