162 BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 



concave proximal border; tlie peristome is thin, little salient, notched, and bears a 



small]|very[inconstant[supraoral avicularium. On each side of the apertura there 



are two small straight avicularia, without pivot, the point above. 



,, . . X {ha = 0.06 mm. rj ■ fi2 = 0.40mm. 



Measurements. — ^Apertura, „ „ . Zooeoa , ^ on ™™ 



^ |Za = 0.04mm. lZ2 = 0.20mm. 



Affinities. — This species is quite close to Escharipora stellata Smitt, 1872, a 

 recent species off the coast of Florida, in the ensemble of its characters. It differs 

 from it in the vertical direction of the oral avicularia, in the less low position of the 

 latter, and in the much smaller number of frontal perforations. Escharipora 

 stellata MacGillivray, a recent species from Australia, is not the species of Smitt, 1 872, 

 but it is undoubtedly of the same genus. 



We are absolutely ignorant of the hydrostatic system of this group called 

 Escharipora by Smitt, 1872. MacGillivray believed that it belonged to the Adeo- 

 nidae. Levinsen considered the stellate pores as ascopores. It has seemed to us 

 that one of our specimens had a gonoecium with transverse apertura, but it is 

 necessary to await more detailed zoological study in order to classify this group of 

 species. 



Occurrence. — Lower Miocene (Chipola marl) : Chipola River, Calhoun County, 

 Florida (rare). 



Cotypes.—C&t. No. 68676, U.S.N.M. 



Genus ANARTHROPORA Smitt, 1867. 



(For description, see Bulletin 106, U. S. National Museum, p. 430.) 



Levinsen classified this genus doubtfully in the Escharellidae, where we also 

 placed it in our monograph on the North American Early Tertiary Bryozoa. The 

 absence of the ovicell, the nature of the frontal, and the analogy with certain species 

 of Adeonellopsis indicate that the genus is better placed in the Adeonidae. 



Family HIPPOPODINIDAE Levmsen, 1909. 

 Genus METRARABDOTOS Canu, 1914. 



(For description, see Bulletin 106, U. S. National Museum, p. 533.) 

 METRARABDOTOS c6lLIGATUM Cann and Bassler, 1919. 



Plate 4, figs. 3-12. 



1919. Melrarabdotos colligatum Canu and Bassler, Geology and Paleontology of the West Indies, 

 Bryozoa, Publications of the Carnegie Institution of Washington, no. 291, p. 95, pi. 4, 

 figs. 3-12. 



Description. — The zoarium is free, bilamellar, attached to algae by a small, 

 expanded base and bent upward like a crank; the fronds are large, bifurcated, but 

 narrow. The zooecia are distinct, separated by a salient thread, long and narrow; 

 the frontal is smooth, convex, surrounded by a line of large areolar pores often 

 separated by short costules. The apertura is suborbicular; the peris tomice is oval 

 with a proximal pseudorimule. There are sometimes two quite inconstant, small. 



