BRYOZOA OF THE PHILIPPINE REGION 395 



The known species of the genus are as follows: 



Tetraplaria gryllus, new species Pacific. 



Tetraplaria (Pollaploecium) brevis Canu and Bassler, 1927. Pacific. 



Tetraplaria (Diploecium) simplex Robertson, 1921 Indian Ocean. 



Tetraplaria (Arborella) dichotoma Osburn, 1914 Gulf of Mexico. 



Tetraplaria (Onchopora) mutria Busk, 1855 Pacific. 



Tetraplaria (Cellaria) schreibersi Reuss, 1869 Eocene (Priabqnian). 



Tetraplaria australis Tenison-Woods, 1878 Miocene. 



Tetraplaria (Schizoporella) australis MacGillivray, 1895 



(not Tenison-Woods) Miocene. 



Tetraplaria (Smittea) laevigata Waters, 1881 Miocene. 



Tetraplaria {Bigemellaria) pedunculata MacGillivray, 1895. Miocene. 



Tetraplaria caudifera Canu and Bassler, 1920 Eocene (Jacksonian). 



Tetraplaria tuberculala Canu and Bassler, 1920 Eocene (Jacksonian). 



Pollaploecium Maplestone, 1909, in which the cells of the segments 

 are facing all ways and Diploecium Kirkpatr/ick, 1888, in which the 

 segments have only two cells, belong 

 probably to the same genus. The differ- 

 ences are only zoarial. We have main- 

 tained them because we have not had 

 opportunity to study them directly. 



o 



TETRAPLARIA GRYLLUS, new species 



Plate 55, figs. 6-10 ^ 



Description. — The zoarium is articulated. 

 The segments are quadrangular, narrowed 

 at the base, enlarged at the summit. The Fig. 151.— Tetraplaria 

 zooecia are arranged in four longitudinal gryllus, new species. A. 

 : r - i - u au mu Operculum, X85. B. 



ranges at right angles to each other. The Longitudinalsection)X2 5 

 zooecia are distinct, separated by a salient 



thread, much elongated, lozenge shaped; the frontal is very convex, 

 granular, perforated by a large number of small tremopores. The 

 apertura is orbicular and bears proximally a broad semicircular sinus. 

 The peristome is complete, salient; the operculum bears two muscular 

 attachments, distant from the border and various ornaments more or 

 less constant. The ovicell is endozooecial, large, very convex, of the 

 same structure as the frontal. 



Measurements. — 



Apertura!^ - ; 1 ,? mm ' Zooeciaif z ^ mm ' 



F Ua=0.16mm. U2-0.40mm. 



Structure. — This charming species is very constant in its char- 

 acters with the exception that the separating threads of the opposite 

 zooecia are not always adjacent. The number of cells in a longi- 

 tudinal row varies from 3 to 5. The operculum is a veritable humor- 

 ous caricature but the two muscular attachments are alone very con- 

 stant and the transverse bands appear somewhat variable. In longi- 

 tudinal sections the walls are thin and moniliform, the zooecia are 



