FOSSIL BRYOZOA FROM THE WEST INDIES. 85 



Measurements. — Opesium: ho = 0A0 mm., lo = 0.25 mm. ; zooecia: Lz = 0.65 

 to 0.70 mm., Zz = 0.35 mm. 



Affinities. — The group of inferior opesiular spines was certainly 

 dissymmetrical; trace of the lateral spines is scarcely visible on our 

 specimens. 



This species differs from Hemiseptella denticulata Smitt, 1872, in the 

 absence of nodosities in the interzocecial angles and in the non-tri- 

 foliate opesium. 



It differs from Hemiseptella tenuis Desor, 1848, in the larger micro- 

 metric measurements and in the more fragile and less numerous spines. 



Occurrence. — Lower Miocene (Bowden marl) , Bowden, Jamaica (rare) . 



Hemiseptella lata, new species. 

 (Plate 2, figure 4.) 



The following is a description of this species : 



The zoarium incrusts Metrarabdotos. The zooscia are distinct, little elon- 

 gated, wide, subrectangular; the mural rim is thin. The opesium is elliptical 

 or orbicular, never symmetrical; the cryptocyst is short, little deep, irregular; 

 the opesiular indentations are represented by two lateral dissymmetric con- 

 cavities and are often separated by a wide and serrate denticle. 



Measurements. — Opesium: ho = 0.30 mm., lo = 0.22 to 0.30 mm.; zooecia: 

 Lz = 0.42 mm., Zz = 0.30 to 0.32 mm. 



Affinities. — It is always difficult to characterize a species from the 

 study of a single specimen. Exteriorly the zooecia have the form of 

 certain zooecia observed in Acanthodesia savartii Savigny-Audouin, 

 1826; it differs from it in its non-symmetric opesium and in two ope- 

 siular sinuosities. 



This species differs from Biflustra savarti Smitt, 1872, which is not 

 its perhaps the species of Audouin, in the more constant development of 

 cryptocyst and in the nature of its zoarium, which does not incrust algae. 

 The proximal denticle has been clearly observed on these zooecia. 



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

 (Bluff 3), Santo Domingo. 



Genus CUPULARIA Lamouroux, 182 1. 



Cupularia umbellata Defrance, 1823. 



(Plate 1, Figures 5 to 7; Plate 2, Figures 17 to 21.) 



Discoporella denticulata Gabb and Horn, Monograph of the Fossil Polyzoa of the Secondary 



and Tertiary Formations of North America, Journal Academy of Natural Sciences 



of Philadelphia (2), V, p. 142, plate 20, fig. 25, 1862. 

 Cupularia umbellata Canu, Iconographie des Bryozoaires fossiles de l'Argentine, Anales del 



Museo National de Buenos Aires, XVII, p. 275, plate v, figs. 4, 5, 1908. (See for 



complete bibliography.) 

 Cupularia umbellata Canu, Bryozoaires fossiles du Sud-ouest de la France, Bulletin de la 



Societe Geologique de France (IV), IX, p. 448, 454, plate xvi, figs. 16, 17, 1909. 



(Regional bibliography.) [ 



Cupularia lowei Norman, On the Polyzoa of Madeira, Journal Lmnsean Society, AJLA, p. 



290, plate 37, figs. 7-12, 1909. 



