MOLLUSCOIDEA. 339 



Planicellaria cylindrica Gabb & Horn. 

 Plate XXIV., Fig. 8. 



1862. Flustrella cylindrica G. & H., Jour. Acad. Nat. Sci. Phil., 



2d ser., vol. 5, p. 161, pi. 20, fig. 49. 

 1864. Flustrella cylindrica Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 4. 

 1868. Flustrella cylindrica Con., Cook's Geol. N. J., p. 723. 



Description. Zoarium consisting of cylindrical or oval (?) 

 branches, with six longitudinal rows of zooecia in the type speci- 

 men, arranged in quincunx. Zooecia divided externally into two 

 subequal regions; the anterior region convex and oval, with its 

 longest diameter the greater, pierced in its center by a circular 

 or oval aperture whose diameter is about one-third the width 

 of the zooecium ; the posterior region is flatter and supports a sub- 

 quadrate labiate process, probably the point of attachment of an 

 avicularium, which is depressed behind and elevated in front; it 

 is truncated above so that the opening is directed forward and 

 upward. 



Remarks. This species resembles the last, differing chiefly in 

 the smaller number of rows of zooscia. 



Formation and locality. Vincentown limesand, near Mullica 

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



Geographic distribution. New Jersey. 



Genus EsCHARiNEUvA d'Orbigny. 



Escharinella altimuralis Ulrich and Bassler n. sp. 



Plate XXIV., Figs. 9-10. 



Description. Zoarium encrusting, zooscia subrhomboidal in 

 outline, about 0.5 mm. in length, with very thin walls. At each 

 angle is a rather large avicularium, subcircular or subelliptical in 

 outline, with walls somewhat thicker than those of the zocecia. 



Remarks. This is a very distinct species, abundant at Vincen- 

 town, which may be easily recognized by its thin walls and 

 prominent avicularia. 



