412 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



less visible; the frontal is convex, very finely granular and porous; 



the tremocyst is very thin. The aperture is small, nonterminal, 



provided with two strong cardelles; the poster is a little wider than 



the anter; the proximal border is convex (mucronated); the peristome 



is thin and little salient. The ovicell is globular, of varied form, closed 



by the operculum. From each side of the aperture arise short setae. 



Measurements. — 



A T .^f 11 ^f^ a = -l 2 mm - n „• I Lz = 0.60 mm. 



Apertura<, ■ _ Zooeciai, 



H lk = 0.12mm. \lz = 0.46-0.50 mm. 



Affinities. — This beautiful species is very well characterized by its 

 large micrometric dimensions. It presents some other interesting 

 features. On the nonmarginal zooecia the setiform spines are short 

 (■=0.15-0.20 mm.) and all equal; they are very long on the contrary 

 ( -=0.60 mm.) on the free side of the marginal zooecia. The marginal 

 dietellae are visible even through the ectocyst which, moreover, is very 

 thin. 



Biology. — Our specimens were living. They were in reproduction 

 in April, 1908. Their spines are very fragile and they can not live 

 in rough waters; further at 170 meters a current alone could disturb 

 the tranquility of the sea. But then in the depth around Anima Sola 

 what cause could bring in the rich plancton which exists there? 



Occurrence. — D. 5217. Anima Sola Island, between Burias and 

 Luzon; 13° 20' N.; 123° 14' 15" E.; 105 fathoms; crs. gy. S. 



Coty pes. —Cat. No. 8220, U.S.N.M. 



Genus MASTIGOPHORA Hincks, 1880 



MASTIGOPHORA PESANSERIS Smitt, 1873 



Plate 58, figs. 4-8 



1909. Schizoporella pesanseris Waters, Marine biology of the Sudanese Red 



Sea, Bryozoa, Journal Linnean Society, Zoology, vol. 21, p. 169. 

 1909. Escharina pesanseris Levinsen, Morphologic and Systematic Studies on 



the Cheilostomatous Bryozoa, p. 326, pi. 18, fig. 1. 

 1909. Escharina pesanseris Norman, The Polyzoa of Madeira, Journal Linnean 



Society, Zoology, vol. 30, p. 302, pi. 40, fig. 7. 

 1914. Escharina pesanseris Osburn, The Bryozoa of the Tortugas Islands, 



Pub. No. 182, Carnegie Institution of Washington, p. 207. 



1927. Mastigophora pesanseris Canu and Bassler, Bryozoaires des lies Hawai, 



Bulletin de la Soci6t6 des Sciences de Seine et Oise, ser. 2, vol. 8, p. 36 

 (ref.), pi. 8, fig. 5 (Biology). 



1928. Mastigophora pesanseris Canu and Bassler, Bryozoaires du Bresil, Bulle- 



tin de la Soci6te" des Sciences de Seine et Oise, ser. 2, vol. 9, p. 96, pi. 9, 

 fig. 1 (Biology and geographic distribution). 



Measurements. — 



\Dertura^ a = - 12 "" - 14 mm - Zooecia!^ = - 6 °-°- 80 mm - 

 Apertura| Za = () 1Q mm Z/0oecia U 2 = 0.40-0.50 mm. 



Affinities. — Waters, 1909, says " MastigopJiora was separated from 

 Schizoporella as having vibracula; but this species has avicularia, and 



