FOSSIL BRYOZOA FROM THE WEST INDIES. 99 



This species must not be confounded with Mamillopora cupula 

 Smitt, 1872. It differs from it in its ovicell, which is not bilobate, and 

 in its ovarian zooecia, which are not larger than the others. 



Occurrence. Lower Miocene (Gatun formation), Banana River, 

 Costa Rica, D. F. McDonald, collector, 1911; lower Miocene (Bowden 

 horizon), Rio Gurabo (zone D), Rio Cana (zone I), and Cercado de 

 Mao, Santo Domingo; Bowden, Jamaica. 



Order CYCLOSTOMATA Busk. 

 Family TUBULIPORID^ Johnston, 1838. 



Genus IDMONEA Lamouroux. 



Idmonea milneana d'Orbigny, 1839. 



(Plate 6, Figures 20, 21.) 



Idmonea milneana d'Orbigny, Voyage dans PAme'rique m6ridionale, V, pt. 4, p. 20, plate 9, 



figs. 17 to 21, 1839. 



Idmonea grateloupi d'Orbigny, PalSontologie francaise, Bryozoaires cretacees, p. 729, 1852. 

 Idmonea milneana Smitt, Floridan Bryozoa, p. 8, plate in, figs. 14-19, 1872. 

 Idmonea milneana Canu, Bryozoaires tertiares des environs de Paris, Annales de Pale"on- 



tologie, III, p. 125, plate 14, figs. 11-13, 1908. (Cites bibliography.) 

 Idmonea milneana Canu, Bryozoaires du Sud-Ouest de la France, Bulletin de la Soci6t6 



Geologique de la France (4), VIII, p. 386, I, p. 451, 1908. 



Our small specimen is not very well preserved, but we feel perfectly 

 certain of it, because we know all its fossil variations.. It is evident, 

 however, that such a determination is always subject to revision. 



Occurrence. Lower Miocene (Bowden horizon), Cercado de Mao, 

 Santo Domingo. 



Geological distribution. Ypresian of England (Gregory) ; Lutetian of 

 Bavaria (Koschinsky) , of Paris (Canu), of the Ariege (Canu) ; Auversian 

 of Biarritz (Canu) ; Latdorfian of Latdorff (Stoliczka) ; Stampian of 

 Germany (Reuss) ; Tortonian of Austria-Hungary (Reuss) ; Sicilian of 

 Italy (Seguenza); Quaternary of Italy (Seguenza). 



Habitat. Cosmopolitan in both hemispheres. In Florida it has been 

 dredged between 26 and 109 meters. 



