28 BULLETIN 16 5, UNITED STATES NATIONAL MUSEUM 



Affinities. — Crassimarginatell a and V aldemunitella were created by 

 Canu in 1900 as artificial subgenera in order to facilitate the determi- 

 nation of the Cretaceous Membranipores. The senior author feels 

 that Norman, 1905, Harmer, 1926, and Hastings, 1930, have been 

 in error in describing them as natural genera and that such interpre- 

 tations should never be permitted by the rules of nomenclature. 

 Membranipora valdemunita Hincks, 1880, and M. crassimarginata 

 Hincks, 1880, having different ovicells, should not remain in the 

 same genus Oochilina, created for them by Norman in 1903. The 

 form of the avicularia cannot be considered as a generic character, 

 because they are inconstant and are organs of adaptation. Thus 

 Crassimarginatell a intermedia, the present species studied, has ovi- 

 cells as in Crassimarginatella and avicularia as in V aldemunitella. 



In establishing new genera we cannot hold only that the simple 

 presence of the avicularia indicates a function indispensable to the 

 colony. It is necessary then to redefine these genera as follows : 



Crassimarginatella : Ovicell hyperstomial, not closed by the oper- 

 culum. Interzooecial avicularia sporadic. 



V aldemunitella: Ovicell hyperstomial, closed by the operculum. 

 Interzooecial avicularia sporadic. 



Occurrence. — Vincentown limesand : Common at Vincentown and 

 near Blackwoodstown, N.J. 



Coty pes. —U.S. ISM. No. 73867. 



CRASSIMARGINATELLA NEMATOPOROIDES Ulrich and Bassler, 1907 



Plate 6, Figures 1, 2 



1907. Membranipora nematoporoides Ulrich and Bassler, in Weller, Geol. 

 Surv, New Jersey, Paleontology, vol. 4, p. 336, pi. 24, fig. 13. 



Description. — The zoarium consists of narrow, subquadrangular 

 or subcylindrical, dichotomous branches 0.6 to 0.7 mm in diameter, 

 which are celluliferous on all sides, the zooecia being arranged in 

 from 4 to 6 longitudinal rows. The zooecia are distinct, much elon- 

 gated, oval; the proximal gymnocyst is convex, smooth, occupying 

 about a quarter of the zooecial length ; the mural rim is thick, ellip- 

 tical, salient and bears 5 or 6 pairs of tubercles and some minute 

 distal spines. The opesium is elliptical, regular, elongated, terminal. 

 The ovicell is hyperstomial, not closed by the operculum. The inter- 

 zooecial avicularium is beaklike, with a pivot; it is formed of two 

 portions, the proximal portion, a small ordinary cell and the distal 

 portion bearing a very salient unguiculate beak perpendicular to the 

 zooecial plane. 



Measurements. — ■ 



. [£,2=0.45-0.55 mm. ~ . [^0=0.3-0.35 mm. 

 Zooecia [ u=025 _ ^ mm . °P esmm {z<>=0.15-0.17 mm. 



