ABT. 14 FOSSIL AND EECENT BRYOZOA' — CAISTU AND BASSLER 131 



Genus TREMOSCHIZODINA Duvergier, 1921 



1921. Tremoschizodina Duvergier, Bryozoaires du Neogene de I'Aquitane. 

 Actes de la Soci6t6 Linneenne de Bordeaux, ser. 72, p. 36. 



The ovicell is endozooecial. The aperture has a very broad proxi- 

 mal sinus. The frontal is a tremocyst surmounting a thin olocyst. 

 The avicularium is parietal and very rare. 



Genotype. — Tremoschizodina pisciformisDuYergieT, 1921 (Miocene). 



Range. — Miocene (Helvetian) — Recent. 



This remarkable genus was discovered by Duvergier, in the Helve- 

 tian in the vicinity of Bordeaux, France. We have observed that 

 Gemellipora lata Smitt, 1873, belongs to the same genus. Finally we 

 discovered a magnificent and vigorous species in the Philippines, 

 Tremoschizodina crassa, living in the Sulu Archipelago and in the 

 China Sea. ' 



This is an equatorial genus but passes somewhat beyond the line 

 of the Tropics. The species appear to be extremely sensitive to cold 

 and can not Hve at a temperature less than 9° C. 



TREMOSCHIZODINA LATA Smitt, 1873 



Plate 21, Figures 1, 2; text Figure 28 



1873. Gemellipora lata Smitt, Floridan Bryozoa. Svenska Vetenskaps- 

 Akademiens Handlingar vol. 11, p. 36, pi. 7, fig. 157. 



,, ^ . ^ f^a = 0.16 mm. 



Measurements. — Aperture^ 7 



^ [la = 0.13 mm. 



. ^ / • n Tj7ia = 0.14 mm. 

 Aperture (oTicelled)^;^^^ jg ^^ 



ry . !Lz = 0.50 mm. 

 ZiOoecia<^7 „ „„ 



|is = 0.36 mm. 



Structure. — Smitt found only a single nonovicelled specimen. For- 

 tunately, we have had the chance to discover the ovicell. It is endo- 

 zooecial, small, and somewhat convex. 

 This species must, therefore, be classed 

 in the genus Tremoschizodina Duvergier, 

 1921. 



The apertura figured by Smitt is per- 

 fectly exact. That of the ovicelled zoo- 



. . , , IT • 1 1 Fig. 28.— Tremoschizodina LATA Smitt, 



ecia IS somewhat larger, elliptical, and 1873. a. operculum of ordinaet 

 transverse. The operculum is formed of zooecia, x 85. i. operculum of 



. ., ovicelled zooecia, X 85 



two parts corresponding to the anter and 



poster and bordered interiorily by a sclerite on which the opercular 



muscles are probably attached; there is no other ornament visible. 



It is yellow colored and strongly chitinized. The axis of rotation i& 



formed by two chitinous cardelles, a phenomenon rather rare in ih& 



Cheilostomata. 



The frontal is formed of an olocyst surmounted by a detachable and 

 very thin tremocyst. On the young zooecia the frontal forms a very 



