BRYOZOAN FAUNA OP VINCENTOWN LIMESAND 29 



Affinities. — It is difficult to class this species generically. Its re- 

 markable avicularium is unique and characterizes it excellently. In 

 spite of our views in the past, our new studies on the recent species 

 no longer permit us to give too great importance to the avicularia in 

 the general classification. 



Occurrence. — Vincentown limesand: Vincentown, N.J. (rare). 



Cotypes.— U.S.N.M. No. 52602. 



Genus CALLOPORA Gray, 1848 



CALLOPORA JERSEYENSIS Ulrich and Bassler, 1907 



Plate 6, Figures 7-10 



1907. Membra ni pora jerseyensis Ulbich and Bassler, in Weller, Geol. Surv. 

 New Jersey, Paleontology, vol. 4, p. 336, pi. 24, fig. 3. 



Description. — The zoarium is free, bifoliate, with broad fronds, 

 flat or undulated. The zooecia are distinct, separated by the in- 

 teropesial avicularian chambers, elongated, elliptical; the mural 

 rim, visible only on the young zooecia, is thin, salient. The opesium 

 is deep, elongated, elliptical. The ovicell is hyperstomial, not closed 

 by the operculum, convex, smooth, marginated on its free proximal 

 border. There are four pairs of avicularia usually around each 

 opesium; they are adjacent to one another, elliptical with a pivot, 

 diversely oriented. 



Measurements. — 



. fZs = 0. 6-0. 9 mm. ~ [ho = 0. 42-0. 5 mm. 



Z °° eCia \te = 0. 35-0. 45 mm. 0pGSia |/* = 0.25-0.3 mm. 

 14 zooecia in 4 sq. mm. 



/Structure. — This beautiful species is well characterized by its 

 interopesial avicularia. They form a calcareous layer or epicalcifi- 

 cation between the zooecial mural rims, which are quite separated 

 from one another, as can be verified in the young zooecia. They 

 are grouped principally around the opercular valve (that is. the 

 distal part of the opesium) to the number of 4; 2 belong to the 

 proximal zooecium and 2 to the distal zooecium. But the gemma- 

 tion, often irregular, disarranges this order, and then each opesium 

 appears simply surrounded by 8 avicularian chambers adjacent but 

 distinct and separated by a shallow furrow. These adventitious 

 avicularia are quite large, but even on well-preserved specimens it 

 is hardly possible to observe their orientation because of their sym- 

 metry. If we suppose that their smaller orifice is placed at the 

 slightly narrowed end, most of them are oriented toward the base 

 (downward). In tangential sections they are seen to be interopesial. 

 The primoserial avicularia are transverse. 



This intense epicalcification is a perfectioning of the pores of 

 calcification observed in the genus Craspedopora Canu and Bassler, 



