MOLLUSCOIDEA. 349 



mm. in length. Zocecial apertures situated anteriorly, small, 

 transversely subelliptical in outline or semicircular by reason of 

 the straightening of the posterior margin, bordered by a rather 

 broad, slightly-raised rim. Surface of the zocecia, back of the 

 aperture, moderately convex. Avicularia rather abundant, large 

 and conspicuous, frequently more or less elongate. 

 ' Formation and locality. Vincentown limesand, Vincentown 



(154). 

 Geographic distribution. New Jersey. 



Genus MONOPORIXLA Hincks. 

 Monoporella exserta (Gabb and Horn). 



Plate XXV., Figs. 5-7. 



1862. Cellepora 'exserta G. & H., Jour. Acad. Nat. Sci. Phil., 



2d ser., vol. 5, p. 125, pi. 19, fig. 6. 

 1864. Cellepora exserta Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 3. 



1868. Cellepora exserta Con., Cook's Geol. N. J., p. 722. 

 1905. Cellepora exserta Johns., Proc. Acad. Nat. Sci. Phil, 



1905, P. 5- 



Description. Zoarium usually small and radiating, encrusting 

 shells and other bryozoa. Zocecia arranged irregularly, subovate 

 in outline, very prominent, presenting the appearance of being 

 attached by only a portion of the base, somewhat barrel-shaped, 

 contracted towards the base and also towards the aperture, 

 aperture terminal, large, round or transversely elliptical, directed 

 upwards and forwards with a slight thickening or lip about the 

 margin. 



Remarks. The zoaria of this species are usually small, con- 

 taining from 30 to 40 zocecia, but larger ones occasionally occur 

 with one hundred or more zocecia. The species can be recognized 

 by the exsert, irregularly placed zocecia, which give the zoaria, 

 even to the naked eye, an unusually rough appearance. 



Formation and locality. Vincentown limesand, near Mullica 

 Hill (Gabb and Horn), Vincentown (154). 



Geographic distribution. New Jersey. 



