NORTH AMKUIr.VX E.UMA TERTIARY BRYOZOA. 



549 



triry. the frontal tubules which are much developed about the ascopore; this is a 

 fundamental difference. We are also ignorant of the physiological purpose of the 

 development of the peristomial tubules 



The length of the tubules is ahvay^ very variable, as can be noted on the figured 

 sections (figs. 6, 7). 



We have been rather fortunate in reconstructing a part of the zoarium, the 

 dimensions of which ought to 

 attain about four or five centi- 

 meters in length. 



It is very easy to distinguish 

 this species from all known 

 forms. 



We have not had the chance 

 to discover the ovicell in the 

 eight sections which have been 

 studied. 



Occurrence. Middle Jack- 

 xmian: Lenuds Ferry, South 

 Carolina (common). 



Cotypes. Cat. No. G4187, 

 U.S.X.M. 



Genus TUBIPORELLA Levinsen, 

 1909. 



1909. TubiporcJla LEVINSEN, Mor- 

 phological and System- 

 atic Studies on Cheilosto- 

 matous Bryozoa, p. 305. 



A membraneous opercnlar 

 valve. A vestibular arch, each 

 zooecium with one or two avicu- 

 laria at the height of the asco- 

 pore. The colony occurs as a 

 free, foliaceous expansion with a 

 single layer of zooecia (Levin- 

 >en ) . 



Genotype. Tubiporella (/.</; /<///) n/,i</i,/,'0f<tris MacGillivray, 1882. 



Range. Miocene Eecent. 



FIG. 162. Genus Siphonicytam Busk, 1884. 

 A-C. Siphonicytara semdata Busk. 18S4. A. Frontal side 

 of zooeduni. enlarged. B. Zoarium, natural size. C. Dor- 

 sal side showing radical tubes. (A-C after Busk, 1884.) 



Genus SIPHOMCYTARA Busk, 1884. 



ftiiilioniriitara ~Busl;, Report on the I'nly/'.a collected \<\ II. M. S. rlnilli iiiirr. p. 101. 

 Busk, in 1884, placed in thi- family his new genus X!/>/it>iiic>/t<-/m. specimens 

 of which have never been found since and for which reason it has not been possible 

 to make supplementary studies His original description and figures follow. 



