164 BUIXETIN 125, UNITED STATES NATIONAL, MUSEUM. 



of the ovicell. The species is quite variable and we have figured the principal 

 variations. 



Occurrence. — Lower Miocene (Bowden horizon) : Cercado de Mao and Rio Cana 

 Santo Domingo (common) . 



Cotype.—C&t. No. 68677, U.S.N.M. y 



METRARABDOTOS LACRYMOSUM Canu and Bassler, 1919. 



Plate 8, figs. 1-10. 



1919. Metrarabdotos lacrymosum Canu and Bassler, Geology and Paleontology of the West Indies, 

 Bryozoa, Publications of the Carnegie Institution of Washington, no. 291, p. 96, pi. 3, 

 figs. 1-10. 



Description. — The zoarium is free, bilamellar, bifurcated, narrow, with rectan- 

 gular fronds, and fastened by a little expanded base. The zooecia are distinct, 

 little elongate, rectangular, surrounded by large areolar pores more or less separated 

 by the costules. The apertura is oblique, semielliptical, divided in front by a 

 rounded and perforated sinus. The ovicelled zooecia are quite wide; the ovicell 

 is endozooecial; it is little salient, finely punctate, and ornamented with inter- 

 areolar costules. On each side of the apertura there are two large, triangular, 

 salient avicularia with their point directed upward. 



,, . A ^ fi'ia = 0.18 mm. „ . fis = 0.70-0.74 mm. 



Measurements. — Apertura , . , . Ziooecia , „ r.o r, o^ 



^ (fo = 0.14mm. Us =0.28-0.30 mm. 



Affinities. — The characteristics of this species are the two large, oral avicularia 

 which hang from each side of the apertura like two large tears. They are very 

 irregular. 



This species differs from Aletrarahdotos colligatum from the same geological 

 horizon, in its little expanded and nonprehensile base, in its nonclaviform fronds, 

 and in the presence of large, oral avicularia. It differs hom Metrarabdotos moniliferum 

 Milne-Edwards, 1838, in its much less costulated ovicell and in the absence of a 

 spine in the oral sinus. 



Occurrence. — Lower Miocene (Bowden marl) : Bowden, Jamaica (common) . 



Cotypes.— Cat. No. 68678, U.S.N.M. 



METRARABDOTOS AURICULATUM, new species. 



Plate 31, figs. 1-9. 



Description. — The zoarium is bilamellar and formed of large, long, narrow, 

 bifurcated fronds. The zooecia are distinct, separated by a salient thread, clavi- 

 form; the frontal is narrow, little concave, surrounded by numerous areolar pores, 

 separated by salient costules. The peristomice bears a rather deep proximal sinus 

 at the base of which there are two lateral condyles limiting the orifice of the com- 

 pensatrix; the apertura, buried at the base of the peristomice, is elliptical, a little 

 elongated; the peristome bears two lateral avicularia. The ovicell is endozooecial, 

 quite large; its superior wall is convex and costulate; its apertura is large and 

 transverse. 



Measurements.-ApertuvJh^^^^-'l °^^- Zooecia(t = ?-!°"°-^° °^- 



^ [Za = 0.16mm. U2 = 0.40mm. 



