NORTH AMERICAN EARLY TERTIARY BRYOZOA. 775 



(Canu) ; Auversian of the Pyrenees (Canu) ; Latdorfian of Germany (Stoliczka) ; 

 Rupelian (=Stampian) of Germany (Schreiber) ; Tortonian of Austria-Hungary 

 (Manzoni) ; Sicilian of Italy (Seguenza, Neviani) ; Quaternary of Italy (Seguenza- 

 Neviani) ; Miocene of New Zealand (Stoliczka) and of Australia (Waters, Mac- 

 Gillivray). 



Habitat. Mediterranean. Indian Ocean: Zanzibar (16 meters). Antarctic 

 Ocean: Terre del Fuego, Patagonia (13-48 meters), Kerguelen Island (122-244 

 meters. Atlantic Ocean: Azores (733 meters), Chonos Archipelago, Florida 

 (36-609 meters). Pacific Ocean: Fiji Islands, Queen Charlotte Islands, Australia. 



Plesiotypes.C&t. No. 65351, U.S.N.M. 



IDMONEA ARCUATA, new species. 

 Plate 135, figs. 16-20. 



Description. The zoarium is short, free, arched, lobate, with transverse sec- 

 tion wide and elliptical. The fascicles are quite salient, regular, arranged alter- 

 nately on each side of the median axis; they are formed of six to eight zooecia. 

 The tubes are little visible, small, nearly equal on the same fascicles ; the peristome 

 is rectangular. The basal lamella is smooth with the convex striations rather 



widely spaced. 



Diameter of the tubes 0.10 mm. 



Distance between the fascicles 0.24-0.28 mm. 



Width of the fascicles 0.12-0.14 mm. 



Width of the zoarium 1.6 mm. 



We have not discovered the ovicell of this charming species ; we are therefore 

 not certain of its generic classification other than certain lobes are claviform, a 

 condition which does not exist in the typical Idmonea. Moreover, our specimen 

 from Lenuds Ferry is incrusting a bryozoan. 



Affinities. This species differs from Idmonea petri D'Archiac, 1846, in the 

 lesser distance between the fascicles (0.28 and not 0.40 mm.) in its smaller tubes 

 and the absence of the rectilinear form of the zoarium, and in a larger number of 

 tubes (eight) to the fascicle. 



It much resembles Idmonea tacta in its micrometric measurements, but differs 

 from it in a greater interfascicular distance (0.24 and not 0.20 mm.), in a greater 

 number of tubes to the fascicles (eight and not six), and in its nonlinear zoarium. 



Occurrence. Middle Jacksonian: Wilmington, North Carolina (rare); near 

 Lenuds Ferry, South Carolina (very rare). 



Cotypes.Ca.t. No. 65344, U.S.N.M. 



IDMONEA SLOANI, new species. 

 Plate 135, figs. 21-26. 



Description. The zoarium is free, linear, bifurcated, with triangular trans- 

 verse section which is higher than wide. The fascicles are salient, close together, 

 arranged alternately on each side of a median crest; they contain four or five 



Measure-men ts. 



