NORTH AMERICAN EARLY TERTIARY BRYOZOA. 



225 



mb 



Genus SMITTIPORA Jullien, 1881. 



1SS1. Smittipora JULLIEN, Note sur line nouvelle division des Bryozoaires Cheilostomes, 

 Bulletin Societfi Zoologique de Fi-iince, vol. G, p. 14. 



The cryptocyst which is deep and concave, exhibits three facets of which 

 the two lateral ones are formed by the mural rim; the two lateral furrows which 

 separate the mural rim from the cryptocyst are constant. The mandible of the 

 onychocellarium is bimembranous ; 

 the onychocellarium and its opesium 

 are little different from the zooecia. 



Genotype. Smittipora ( Vincu- 

 /,///,/} nhi/Kx'/cola Smitt, 1873. 



Range. Senonian Recent. 



Historical, It is not certain that 

 the European Cretaceous species 

 classified by Jullien in this genus 

 really belong to the group of Vincu- 

 laria abyssicola Smitt. To the best of 

 our knowledge the ovicells have never r JK ,. 

 been observed on the fossil forms, and 

 Smitt's species has not yet been re- 

 discovered. We have been unable to 

 make any new observations on the 

 specimens studied from the Midwayan 

 which are of the type observed in the 

 European Cretaceous. We are there- 

 fore obliged to follow Jullien's classi- 

 fication as Canu did in 1900. 1 



Neither Gabb and Horn in 1862 

 nor Ulrich and Bassler in 1907 have 

 intimated the existence of Smittipora in the American Cretaceous. If this be con- 

 firmed, it will be necessary to admit that at the beginning of the Eocene a change 

 occurred in the direction of the Atlantic marine currents. 



SMITTIPORA MIDWAYANICA, new species. 



Plate 4, figs. 1G-19. 



Description. The zoarium is vincular, articulated (?), formed of cylindrical 

 segments containing eight longitudinal series of zooecia. The zooecia are much 

 elongated, hexagonal, confluent through their mural rims; the cryptocyst is deep, 

 very narrow, as long as the opesium, little distinct from the mural rim. The 

 opesium is elliptical. 



, ~ . f^0=0.16mm. . f2 = 0.34 mm. 



Measurements. Opesium 7 _ nnQ Zooecium^ 



A 



FIG. 59. Genus Smittipora Jullien, 1881. 

 A-C. Smittipora ( Vincularia) abyssicola Smitt, 1872. 

 A. Zoarium in the vincularian method of growth. B, 

 C. Incrusting zoaria. (After Smitt, 1872, and Ilincks, 

 1881.) cry, cryptocyst; mb, mandible; op, opesium; 

 r, channel of the cryptocyst. 



7 

 lfo=O.OS mm. 



3=0.16 mm. 



"Canu. Revision des Bryozoaires du Crtac6 figures par D'Orbigny, Bulletin Societe Gologique de 

 France, ser. 3, vol. 28, p. 407. 



55899 19 Bull. 106 15 



