AHT. 22. GYCLOSTOMATOUS BRYOZOA — CANU AND BASSLER. 137 



Ascosoeciidae in which the ovicell is placed laterally. The tubes 

 are conical, with peristome and with dorsal gemmation. They are 

 placed on the anterior face and arranged in more or less transverse 

 rows. Dactylethrae are developed on the posterior face; the}^ are 

 closed b}' a lozenge-shaped facette, perforated by a longitudinal slit. 



Genotype. — Filicrisina verticillata D'Orbigny, 1852. Campanian, 



The known species of this genus are Filicrisma retifornm D'Or- 

 bigny, 1852; Hornera langethali Marsson, 1887; PJionnopom ir- 

 regularis Marsson, 1887 ; and Spiroclausa procera Hamm. 



Historical.— D'Ovhignj classified this genus in the family Crisini- 

 dae, characterized by the presence of pores on the opposite face. 

 Marsson, 1887, created the genus Pliormopora for an analogous 

 species, but a comparison of thin sections shows that its structure 

 is similar to Filicrisina. Gregory in 1899 classified Filisa^slna in the 

 Diastoporidae, close to Fllispar'sa, from which it differed in the rudi- 

 mentary zooecia. He designated their orifices as small pores of 

 epithecal tubes, which is not at all correct, because there are neither 

 tubules nor vacuoles. He chose as type Filicrisina retiformh, but 

 we have not studied this species in detail. 



FIUCRISINA VERTICILLATA D'Orbiffny, 1852. 



Plate 19, ligs. 1-9. 



1852. Filicrisina verticillata d'Orbigny, Paleoutologie fraucaise, Terraiu 



cr6tac6, vol. 5, p. 911, pi. 769, figs. 5-10. 

 1899. Filicrisina verticillata Gregoey, Catalogue of Bryozoa iu British 



Museum, Cretaceou.s, vol. 1, p. 434, fig. 64 (bibliography). 



The figured ovicells appears to us rudimentary, and better speci- 

 mens are desirable. Under this aspect the ovicell is identical with 

 the sack of the Ascosoeciidae. 



The dorsal (reverse side of Gregory) is very curious. It is orna- 

 mented with lozenge-shaped areas bounded by salient threads, the 

 superior angle of which is perforated by a longitudinal slit with 

 salient peristome. A second calcareous layer covers this side, in 

 which case the lozenge-shaped areas are smaller or poorly indicated 

 and the small pores are rounded. 



On the frontal (obverse side of Gregory) the peristomes are ar- 

 ranged in transverse, oblique rows or more rarely in quincunx. 



The longitudinal section indicates the true nature of these ex- 

 terior features. The tubes are conical, with dorsal gemmation and 

 identical in structure with those of Filisparsa, Entalophora. 

 Idmonea^ etc., but they are aborted on the dorsal face and trans- 

 formed into dactyletlirae. The lozenge-shaped areas of the dorsal 

 are therefore the lacettes which close the dactylethrae, and there 

 are therefore no epithecal tubules, as described by Gregory in 1899. 



