BRYOZOA OF THE PHILIPPINE REGION 415 



Affinities. — The beak of the avicularium expands often into a 

 spatulate form in order to receive a wide mandible. This species is 

 therefore very close to Mastigo ph-ora pesanseris Smitt, 1872, and 

 differs simply in its much larger zooeeial dimensions. 



Biology. — All our specimens were ovicelled; some were living. 

 The latter were in reproduction April 22, 1908. 



Occurrence— D. 5217. Anima Sola Island; 13° 20' N.; 123° 14' 

 15" E.; 105 fathoms; crs. gy. S.; 17.2° C. 



Coty pes. —Cat. No. 8225, U.S.N.M. 



MASTIGOPHORA BACULIFERA, new species 



Plate 58, figs. 9, 10 



Description. — The zoarium encrusts nullipores. The zooecia are 

 distinct, separated by a deep furrow, elongated, oval or clavate; the 

 frontal is convex and formed by a tremocyst with very small pores; 

 it bears a dozen large spines around the aperture in the form of 

 small staffs. The aperture is semicircular with a very narrow linear 

 rimule; the peristome is little apparent. The ovicell is amall, recum- 

 bent, globular, closed by the operculum. The aperture of the ovi- 

 celled zooecia is larger (0.16 mm.). 



Measurements. — 



. fk = 0.14 mm. „ . LLz = 0.60-0.70 mm. 



Aperturau Zooecia, __ 



[m = 0.14 mm. Uz = 0.50 mm. 



Affinities. — The length of the staff-like spine is rather variable; it 

 can measure a half millimeter. They are not arranged at all as in 

 Crep'alacautha since they are placed on the tremocyst; they cor- 

 respond to the tremopores and not to the dietellae. Levinsen called 

 them acropetalous (or annular); they grow by means of a membrane 

 at their free end. 



A certain number of species are thus ornamented with spines 

 like small staffs; Schizoporella biserialis Hincks, 1885, Schizoporella 

 arachnoides MacGillivray, 1882, Lacuna (Schizoporella) chondra 

 Marcus, 1921, and Schizoporella patagonica Waters, 1905 ( S. 

 longispinata Busk, 1852). The affinities of M. baculifera are espe- 

 cially with the last, principally in its micrometric measurements; 

 it differs in the greater (double) number of spines. 



Biology. — We possess only two colonies of a dozen cells of this 

 charming species. It is extremely fragile and can live only in very 

 calm waters. It was in reproduction February 15, 1908. This 

 species lives in the same localities as Mastigophora pesanseris Smitt, 

 1872. The substitution of spines for avieularia is not then a special 

 adaptation to a medium determined by depth, temperature and 

 salinity; their presence appears to reveal rather a particular kind of 

 capture or more exactly a special means of capture of certain very 

 mobile organisms. 



