NORTH AMEEICAUr lATEE TERTIARY AND QUATERNARY BRYOZOA. 1 9 



Genus PYRIPORA D'Orbigny, 1852. 



(For description see Bulletin 100, U. S. National Museum, p. 78.) 



PYRIPORA BREVICAUDA, new species. 



Plate 9, figs. 2-4. 

 Description.— The zoaiium encrusts Cellepore bryozoa. The zooecia are pyri- 

 fonn, little narrowed behind, elongated, distinct, separated by a furrow; the gym- 

 nocyst is convex and very short. The opesium is elliptical or oval, anterior. 



f/.o = 0.20mm. Zooecia|^^ = ^-^° "^°^- 



Measurements. '-0]yesi&'^ ^^ _ ^'^.^ ^^^ Zooeciaj ^^ ^ ^.^^ ^^ 



Variations.— This small species is of a disconcerting irregularity, especially 

 since the substratum itseK is very irregular. The calcified zooecia bear a large 

 elliptical pore. The heterozooecia are numerous and generally fusiform. The 

 zoarial expansions appear to be flabelliform. 



Occum;ice.— Miocene: Kulms, Carteret County, North Carolina (rare). 



Cotypes.—C&t. No. 68399, U.S.N.M. 



Genus MYSTRIOPORA Lang, 1915. 



1915. Mystriopora Lang, New Uniserial Cretaceous Cheilostome Polyzoa, Geological Magazine 

 ser. 6, vol. 2, p. 002. 



MYSTRIOPORA (?) AREOLATA, new species. 



Plate 33, figs. 1, 2. 

 Description.— The zoarium is incrusting. The zooecia are distinct, separated 

 by a deep furrow, elongated, pyriform: the gymnocyst is short, convex, smooth, 

 much narrowed. The mural rim is thin, garnished all around with hollow spmes; 

 the opesium is large, oval, anterior; between the zooecia are some zooecmles whose 

 opesium is also garnished with some spmes. The zooecia are separated from each 

 other by rectangular areolar spaces. Dietellae are present. 



(/io = 0.4omm. r, ■ fi2 = 0.60mm. 



Measurements.^— Opesm'^^^ ^Q,^. ^^^ z-ooecia^^^ =0.50, mm. 



Affinities.— The Cretaceous genus Mystriopora Lang, 1915, shows also zoo- 

 eciules (although the English authors thought them to be more in the nature of 

 avicularia) and areal spines, but it did not have areolar spaces between the zooecia. 

 Our specimens appear, therefore, to belong to a new genus, although we prefer to 

 employ Lang's name provisionally because the rarity of specimens has not per- 

 mitted us to make a tangential section in order to discover the dietellae and to 

 estabhsh the nature of the areolar spaces. We have observed cases of double and 

 triple regeneration of the polypide. 



This species differs from Memhranipora pedunculata Hincks, 1881, also pro- 

 vided with zooeciules, by the absence of spines and by the presence of areolar spaces. 



Occurrence.— Pleistocene: Santa Monica (Long Wliarf Canyon), California 



(rare) . 



Coty pes. —Ca.t. No. 68400, U.S.N.M. 



TlaThec^tion of measurements ho is the length and (o the «-idth of the opesia, Lz and tz siniilarly the length and width of 

 the zooecia, Lv and Iv the same for the vibraculum, Lon and (on for the onychoeollaria, ha and la for the apertura, etc. 



