NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 



101 



(Busk), of Italy (Manzoni); SiciHan of Italy (Neviani, Waters); Quaternary of 

 Italy (Neviani) ; Pliocene of New Zealand (Waters). 



Habitat- — Arctic Ocean: Kara Sea, Spitzberg, Greenland, Jean Mayen (160-180 

 meters), Alaska (circumpolar species). Eastern Atlantic: North Sea, English 

 Channel, England, Brittany, Gulf of Gascony (166 meters), Spain, Madeira (48 

 meters), Azores (130 meters). Western Atlantic: Woods Hole region (5-32 meters), 

 Florida (14-97 meters). Eastern Pacific: Queen Charlotte Islands, California (213 

 meters). Western Pacific: Japan. Southern Pacific: Australia, New Zealand. 

 Mediterranean: Nice, Naples, Corse (22-110 meters), Ajaccio (280 meters), Boni- 

 facio (55-77 neters), Algeria (121 meters), and north of Morocco (370 meters). 



Plesiotypes.— Cut. Nos. 68544-08546, U.S.N.M. 



Genus STYLOPOMA Levlnsen, 1909. 



1909. Stylopoma Levinsen, Morphological and Systematic Studies on the Cheilostomatous Bryozoa, 



pi. 18 (name only). 

 1920. Stylopoma Canu and Bassler, Monograph North American Early Tertiary Bryozoa, Bull. 



106, U. S. National Museum, p. 359. 



The ovicell is hyperstomial ; it covers the apertura and the avicularia entirely. 

 The frontal is a tremocyst. The apertura is provided with a small linear rimule. 



P4 



\' ■.■.•■■..• *.'^« *^>v.. •. .• ..V 



Fig. 15. — Genus Stylopoma Levinsen, 1909. 

 A.-H. Stylopoma spongiles Pallas, 1766. A. Zooecium, X 40, with an ovicell, the frontal half of 

 which is cut away. B. drawing, X 6, showing an ovicell from the proximal end and distal walls with 

 septulae. C, D. Opercula, X 100. (A-D, after Levinsen, 1909.) E. Zooecia, X 25, showing ovicell 

 and vicarious avicularium. F. A zooecium, X 85, showing the oral denticles from the front. G. 

 Operculum, X 85. (E-G, after Waters, 1918.) 



Genotype. — Stylopoma (EscJiara) spongites Pallas, 1766. Range: Miocene- 

 Recent. 



Levinsen proposed this genus for EscJiara spongites and ScTiizoporella longirostris 

 Hincks, 1886, but having recognized that the size of the rimule upon which lie based 

 it is not a generic character, he suppressed the name. We reestablish the genus, 

 basing it upon the function of the passage of the eggs, which operates in a very 

 different manner from that in Schizopodrella, where the species would otherwise 

 have been placed. The great development of the ovicell above the aperture assures 

 this function. Schizoporella longirostris Hincks, 1886, has the same type of orifice, 

 but not being provided with this ovicell it must be classified in Schizopodrella. 



