108 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



a very irregular area; it is deeply embedded in the distal zooecium. 



In almost all the interzooecial angles there is a large tuberosity. 



Regeneration is frequent. 



Measurements . — 



~ . |Ao = 0.34 mm. n . JLz = 0.70-0.74 mm. 



Opesiumi, . _.. Zooeciumu n ... 



r Uo = 0.30 mm. Its = 0.44 mm. 



Affinities. — Our specimen is well preserved but it is dead so that 

 we are not certain that the operculum closes the ovicell. We judge 

 that as on the fossil forms the distal part of the mural rim was buried 

 by the ovicell. If in the future, this observation be not confirmed it 

 will be necessary to classify the species in Alderina. The species 

 differs from Membranipora marginata Kirkpatrick, 1888, in the 

 presence of interzooecial tuberosities. 



Occurrence.— D. 5179. Eomblon Light, Romblon; 12° 38' 15" N.; 

 122° 12' 30" E.; 37 fathoms; hard S.; 24.2° C. 



Holotype.—C&t. No. 7883, U.S.N.M. 



Genus ALDERINA Norman, 1903 



ALDERINA IMBELLIS, Hinck8, 1860 



Plate 8, fig. 2 



1889. Membranipora imbellis Jelly, A synonymic Catalogue of the Marine 



Bryozoa, p. 151 (bibliography). 

 1903. Alderina imbellis Norman, Notes on the Natural History of East Finmark, 



Annals and Magazine of Natural History, ser. 7, vol. 21, p. 596, pi. 13, 



fig. 8. 

 1907. Membranipora imbellis Calvet, Expeditions scientifiques du Travailleur 



et du Talisman, p. 389 (bibliography). 

 1918. Alderina imbellis Barroso, Notas sobre Bryozoos, Boletin de R. Sociedad 



espanola de Historia Natural, vol. 18, p. 207, fig. 1. 

 1921. Alderina imbellis Duvergier, Note sur les Bryozoaires du N6ogene de 



1'Aquitaine, Actes de la Societ6 Linneene de Bordeaux vol. 72, p. 8. 



This species had been found only in boreal seas, but recently 

 Duvergier discovered it in the Burdigalian of the neighborhood of 

 Bordeaux, where the waters were certainly warm. Its presence in 

 equitorial waters was therefore very probable. We have discovered 

 a good specimen on a nullipore but it was dead. 



Measure merits. — 



~ jho = 0.28 mm. „ JZz = 0.40mm. 



Opesiumu Zooecium, on 



ilo = 0.18-0.20 mm. U2 = 0.30mm. 



Occurrence .— D. 5137. Jolo Light, Jolo; 6° 04' 25" N.; 120° 58' 

 30" E.; 20 fathoms; S. Sh. 



Geographic distribution. — Atlantic: Shores of Ireland and Shetland 

 Islands; Norway, North Sea at the Kattegat, Gulf of Gascony (550 

 meters) and at Santander. 



Geologic distribution. — Miocene (Burdigalian): Cestas (Gironde), 

 France (Duvergier). 



Plesiotype. —Cat. No. 7884, U.S.N.M. 



