176 



BULLETIX 100, UNITED STATES NATIONAL MUSEUM. 



the oral opening. There are three pairs of lateral dietellae and several (four 

 usually) lucid spots in the hind wall. (After Norman.) 



(Monlirun/ in'a} granulifera Hincks, 1880. Recent. 



Genus MEMBROSTEGA Jullien, 1903. 



1IIOM. Mrnilii-osti tut Jrr.LlEN, Bryozoaires provennm ilcs rampages de riliroiiilrllr. ]>. 112. 



The mural rim is provided with four spines on the anterior lips of the orifice. 

 The two outer spines acquire such development that they form by their ramifica- 



tions and their confluence an adventi- 

 tious frontal above the real frontal, 

 seeming to transform the Membrani- 

 poridae into veritable Costulidae. 



(jcnotijin'. Menil>rnxt<-(/n 

 ferox MacGillivray, 18G8. Recent. 



Genus MEGAPORA Hincks, 1877. 



1877. Mi-iiniinrii I-IixcKs. On British Poly- 

 zna. Annals iind Maira/.ini' Nat- 

 ural History, ser. 4. vol. 20, p. 529. 



The zooecia have a strongly devel- 

 oped, partially depressed ervptocyst, 

 and an aperture surrounded by spines 

 and with a well-developed vestibular 

 arch. A compound operculum in which 

 the valvular part and the accessory part 

 are connected by a joint. A few 



pored dietellae. Xo avicularia. Hyperstomial ovicell, not closed by the opercular 



valve. 



(i','nufi/]>f. .Ifi-i/ii/mi-ii rtnt/rnx Hincks, 1877. Recent. 



Genus DISCOFLUSTRELLARIA D'Orbigny, 1851. 



1851. lHx<-ftH.itrrlliiri<i !>'( ">HBK;XY. I'alcniitiilcifiit' frani.-aisp. 'I'crrain Cretsiee, vol. 5, Byi'o- 

 zoaires. p. 507. 



The zoarium is free, orbicular, convex, often conical above, always concave 

 below, composed of zooecia regularly arranged in radiating lines, each beginning 

 with a deformed zooecium with the formation of annular transverse lines. Zooecia 

 round or square, entirely open and deep. The side opposite the zooecial openings 

 presents regular radiating lines not perforated at their surface. (See tig. '24 I, 

 p. 85). 



D'Orbigny. 1S51. Cretaceous. 



FIG. 44. Genus Antropora Norman, lllli:;. 

 A, B. Antroporn iji-iiiuilijir/i Hincks. issi). A. 

 Several zooecia, y. 30. (After Hincks, 1880.) B. 

 View of the back of a zooecium. a. openings re- 

 sulting from the avicularia: below these are seen 

 the pair of lucid bays, and below again the lucid 

 spots. (After Xorman. HIO:5.i 



