APPENDIX. 



TREMOGASTERINA TRUNCATOROSTRIS. new species. 



Plate 47, Fig. 6. 



PfsrHpfioi}. — The zoarium is bilamellar. The zooecia are distinct, separated 



by ii furrow, elongated,' elhptical; the frontal is perforated by a trifoliate orifice 



resulting from the coalescence of three large pores arranged in a triangle; a large 



salient rounded mucro is present and is prolonged somewhat above the aperture. 



The aperture is large, semicircular. On each side there are two large, straight 



avicularia, with pivot, the beak of which is truncated and forms a transverse straight 



line. The ovicell is large salient globular, finely granular. 



„ . » . fj'i,a = 0.17-0.20 mm. „ . [is = 0.60 mm. 



Measurements.— A]iertm&{ , ni^-nor. Zooecia , n o- n (a 



^ I (a = 0.1 /-0. 20 mm. I i2 = 0.3o-0.40 mm. 



Affinities. — This new species differs from Tremogasterina horrida, new species, 

 and T. prohlematica Canu, 1911, in its trifoliate frontal pore arising manifestly from 

 the coalescence of three pores. It approaches in its ovicell Escharipora ? mucronata 

 Smitt, 1872, but differs from it in its large truncated avicularia and in its frontal 

 pores united together. It is indeed an intermediate species between the forms with 

 a large single frontal jKire and those with three pores in a triangle. It is also prob- 

 able that Smitt's species is also a Tremogasterina. If the studies on the living spe- 

 cies prove this to be correct, Smitt's species could then be considered the type of 

 this American genus whose structure has always remained mysterious. 



Occurrence. — Miocene (Bowden horizon): Santo Domingo (very rare). 



Holotype.—Cfit. No. 68685, U.S.N.M. 

 244 



