ART. 22. CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER. 119 



dorsal is very thick, of lamellar structure, and perforated by the 

 scattered vacuoles. These latter appear to come from either side 

 of the basal lamella. 



In transverse section the zoarial walls are very thick; the tubes 

 are almost equal, the smallest being in the vicinity of the dorsal. 



The sulci of the dorsal disappear in tangential sections. These 

 latter show that the calcification operates by very fine and juxta- 

 posed calcareous elements in each lamella. The structure of the 

 zoecial walls on the frontal is identical. 



Occurrence.— Cretuceous (Coniacian) : Tours (Indre-et-Loire), 

 St. Paterne et Villedieu (Loire-et-Cher), France. 



Geologic distrihution. — Coniacian, Santonian, Campanian, and 

 Maastrichtian of France (D'Orbigny, Pergens). 



Plesiotypes.—Q.2iXm collection and Cat. No. 68964, U.S.N.M. 



GRAMMASCOSOECIA, new genus. 



(Greek : gramme., line, in allusion to the black median line of trans- 

 verse sections.) 



The ovicell is a large suborbicular sack. The tubes are cylindri- 

 cal, short, without peristome, with dorsal gemmation. The meso- 

 pores are regular, short, peripheral. The basal lamella is linear. 



Genotijiye. — Grammascosoecia {Cer'wpora) dichotoma Goldfuss, 

 1827. Maastrichtian. 



This genus differs from Ascosoecia, in which the tubes are also 

 cylindrical in the presence of short tubes and in the dorsal gemma- 

 tion on a basal lamella. 



It differs from Reteporidea D'Orbigny, 1850, in the presence of the 

 short tubes, the dorsal and nonperipheral gemmation and the absence 

 of lamellar structure at the zoarial periphery. It differs from the 

 genus Parascosoecia in its cylindrical and nonconical tubes. 



In this abundant family, Ascosoeciidae, each genus is clearly char- 

 acterized either by its system of gemmation or by the form of its 

 tubes, a form which we know corresponds to some special anatomical 

 structure. 



GRAMMASCOSOECIA DICHOTOMA Goldfuss, 1827. 



1827. Ceriopora dichotoma Goldfuss, Petrefacta Germaniae, vol. 1, p. 



34, pi. 10, fig. 9. 

 1851. Eeteropora dichotoma Hagenow, Die Bryozoen der Maastrichter 



Kreidebildung, p. 47, pi. 5, fig. 75. 

 1851. Eeteropora undulata Hagenow, Die Bryozoen der Maastrichter 



Kreidebildung, p. 47, pi. 5, fig. 16. 

 1851. Heteropora ten era Hagenow, Die Bryozoen der Maastrichter Kriede- 



bildung, p. 47, pi. 5. fig. 14. 

 ?1S94. Heteropora dichotoma Hennig, Studier ofver Bryozoerna i .Sveriges 



Kritsystem II, Cyclostomata, Lunds Universitets Arsskrift, vol. 30, 



no. 8, p. 22, fig. 12. 

 20107— 22— Proc. N. M. vol. 61 39 



