FOSSIL BRYOZOA FROM THE WEST INDIES. 89 



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

 and Rio Cana, Santo Domingo, and Bowden, Jamaica. 



Family STEGANOPORELLIDJ2 Levinsen, 1909. 

 Genus STEGANOPORELLA Smitt, 1873. 

 Steganoporella parvicella, new species. 

 (Plate 6, Figures 6 to 9.) 



The following is a description of this species: 



The zoarium is unilamellar, incrusting algse or bryozoa. The zocecia are 

 distinct, elongate, separated by a shallow furrow; the mural rim is thin, 

 salient, finely granular. The cryptocyst is finely porous; the opesium is 

 irregular or semilunar, a little elongate; the polypidian tube forms a rect- 

 angular surface, salient and excentric between the two dissimilar opesiular 

 indentations: The large zocecia (B) are provided with a large distal floor, and 

 the polypidian tube is almost median. 



Measurements. — Opesium of small zocecia: fto=0.34 to 36 mm., Io=0.l6 

 to 0.30 mm.; small zocecia (a): Lz= 0.50 to 0.76 mm., te=0.50 mm.; opesium 

 of large zocecia (jb): fto=0.24 to 0.30 mm., Zo= 0.36 to 0.40 mm.; large zocecia 

 (B) : Lz = 1.00 to 1.10 mm., Zz=0.44 to 0.56 mm. 



Affinities. — The dimensions are quite variable, but they are always 

 smaller than those of Steganoporella magnilabris Busk, which this 

 species resembles in all its other characters. 



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

 (Bluff 3), Santo Domingo, and Bowden, Jamaica. 



Family ASPIDOSTOMnXflS Canu, 1908. 

 Genus LABIOPORA Levinsen, 1909. 



No ovicell; distinct, raised margins; frontal wall of polypidian tube not 

 quadrangular and not surrounded by projecting flanges. Polypide tube bila- 

 biate, on either side connected with the lateral wall by a vertical calcareous 

 lamina; multiporous septula. 



Genotype. — Labiopora crenulata Levinsen, 1909, Recent. 



Labiopora miocenica, new species. 

 (Plate 6, Figure 1.) 



The following is a description of this species : 



The zoarium is unilamellar. The zocecia are elongate, distinct, rectangular; 

 the mural rim is quite thin, round. The cryptocyst is little deep, flat, and 

 formed of a tremocyst superposed on an olocyst perforated with corresponding 

 pores. The opesium is transverse, terminal, or placed at the base of a funnel, 

 formed by the much-developed vestibular arch. The polypidian tube is 

 visible, wide, median. 



Measurements. — Opesium: ho =0.10 mm., to =0.24 to 0.28 mm.; zocecium: 

 Z/g=0.50 to 0.64 mm., Zz=0.32 to 0.34 mm. 



Affinities. — This new species differs from Labiopora crenulata Levin- 

 sen, 1909, in the wide form of the zocecia and in its transverse opesium. 

 The only fragment found has been figured. 



Occurrence. — Lower Miocene (Bowden horizon), Rio Gurabo, Santo 

 Domingo. 



