M< agun 



NORTH AMERICAN EARLY TERTIARY BRYOZOA. 781 



IDMONEA FILIFORM1S, new species. 



Plate 138, figs. 24-27. 



Description. The zoarium is linear, very long, very thin, filiform. The 

 fascicles are little salient, arranged alternately on each side of the median line 

 and extending- very little beyond the zoarial margins; they are formed by two 

 zooecia only. The tubes are visible and convex. The dorsal lamella is round 

 and smooth. 



Diameter of the tubes 0.15 mm. 



Distance between the fascicles 0.90-1.10 mm. 



Width of the fascicles 0.15 mm. 



Width of the zoarium 0.50 mm. 



Affinities. This species presents the aspect of Idmonca viupora D'Orbignv, 

 1852, figured by Beissel, 1865, with two zooecia to the fascicle; but the interfas- 

 cicular separation is much greater. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (rare). 



Cofypes.Cat. No. 65418, U.S.N.M. 



IDMONEA PETRI D'Archiac, 1846. 



Plate 139, figs. 1-13. 



1846. Idmonca petri D'ARCHIAC, Description des fossiles recueillis par il. Thorent dans 



les couches nummulitiques des environs de Bayonne, Memoires de la Societe 



geologique de France, ser. 2, vol. 2, p. 195, pi. 5, fig. 11. 

 1908. Idmonca non reticula BEUTLER. Beitrag zur Kenntnis der Bryozoenfauna der alteren 



Tertiarschichten des siidlichen Bayern, Cyclostomata, Paleontographica, vol. 59, 



p. 226, pi. 23, figs. 17, 18. 

 1911. Idmonca petri CANU, Bryozoaires des Sud-Ouest de la France, Bulletin de la SociSte 



geologique de France, ser. 4, vol. 11, p. 452, pi. 8, figs. 1-2 et 10-11. 



Description. The zoarium is large, linear, or somewhat claviform, compressed, 

 with triangular transverse section. The fascicles are very salient, close together, 

 not extending beyond the zoarial margins, opposite on each side of the median axis : 

 they are formed of four to six equal zooecia. The tubes are visible, flat, often 

 separated by a salient thread. The basal lamella is somewhat concave, excavated, 

 and bordered by a margin of little thickness : it is smooth, slightly striated trans- 

 versely and longitudinally. 



Diameter of the tubes. _ _ 0.14 mm. 



Measuremt nts. 



Distance between the fascicles.- _ 0.30-0.40 mm. 



Width of the fascicles 0.12 mm. 



Width of the zoarium 1.2 mm. 



Affinities. The determination has been made specimen by specimen with the 

 French material, but it may be possible that this species has been described under 

 another name by the paleontologists. Idmonca disticha Reuss, figured by Manzoni 

 in 1877, is exteriorly very close, but the fascicles are clearly alternated, which is 



