AET. 14 FOSSIL AND RECENT BRYOZOA CANU AND BASSLER 37 



form of a small bifid tongue. The ovicell is large, globular, smooth, 



hyperstomial. 



-,, J A i. [^a==0.10 mm. 



Measurements. — Apertureu ^ „^ 



^ Ua = 0.20 mm. 



ri2 = 0.50 mm. 



Zooeclai, ^ ._ 



Us = 0.40 mm. 



Structure. — We have been able to observe only three small dead 

 specimens, and our observations are necessarily restricted. In its 

 arrangement the ovicell is perhaps not closed by the operculum, but 

 we are not positively certain. It is formed of two calcareous pellicles; 

 the superior pellicle is incomplete in front, leaving thus a small frontal 

 cicatrix; it is completed on the two sides by the two bifid tongues, 

 which are, moreover, intimately united. Its orifice is placed lower 

 than the frontal mucro. 



The arrangement of the costules is not at all the ordinary disposi- 

 tion observed in other species of Membraniporella; their extremities 

 are united, leaving between them small, irregularly arranged lacunae. 

 This arrangement is due to the primitive form of the areal spines, 

 which were probably flattened at their extremity like the oral spines. 

 The aspect of the frontal is modified by the form of the spines and 

 by their ramifications. This form of spine in other Membranipores 

 is never a generic character. There is then no serious reason for 

 giving it here a more important significance, Norman, 1909, has 

 noted at Maderia a variety intermedia of Memhraniporella nitida John- 

 ston, 1848, in which the frontal shows modifications quite similar. 



Affinities. — This species differs from Memhraniporella nitida inter- 

 media Norman, 1909, in the presence of two oral bifid tongues and 

 in the absence of avicularia. It differs from Cribrilina alcicornis 

 Jullien, 1882, in which the orifice is also ornamented by four superb 

 palmate spines, in less numerous and wider costules, and in the pres- 

 ence of large linear lacunae. 



Occurrence. — Albatross Station D. 2167, off Habana, Cuba; 23° 10' 

 40" N.; 82° 20' 30" W.; 201 fms.; coral. 

 Albatross Station D. 2319, north of Cuba; 23° 10' 37" 

 N.; 82° 20' 06" W.; 143 fms.; gray coral. 



Coiypes.—C&t. Nos. 7550, 7551, U.S.N.M. 



Genus CRIBRILINA Gray, 1848 



The genus Cribrilina differs from Memhraniporella in the closer 

 spacing of the costules and in their smaller dimensions, their structure 

 in spite of exterior appearances being essentially the same. This 

 difference, including even the perforation of the ovicells in certain 

 species of Cribrilina, is quite feeble. Certainly if this generic dis- 

 tinction is maintained, we will find species with intermediate frontals 

 very diflBcult to classify. At present we have not changed the 



