NORTH AMERICAN EARLY TERTIARY BRYOZOA. 523 



of avicularia with semicircular mandibles. The zooecia are distinct, elongated, 

 separated by a furrow of little depth; the frontal is smooth, convex, ornamented 

 with some lateral areolae. The peristome is large, salient, very thick, and bears two 

 small lateral avicularia; the peristomice is orbicular; it has no peristomie, visible 

 exteriorly. The spiramen is little distant from the peristomice; it, is elongated into 

 the form of a buttonhole. 



,, . f Ae=0.11 mm. . (2=0.35 mm. 



Measur< ments. Jreristomice \ , ' Zooecia' ,. _ 



Affinities. Only the two specimens figured have been found, and we, therefore, 

 have not been able to make a detailed study of the species. 



This species differs from Tcssaradoma ornata in its spiramen which is median 

 and close to the peristomice and in its wide peristome which may attain 0.15 mm. 

 in diameter. 



Occurrence. Upper Jacksonian (Ocala limestone) : West bank Sepulga Kiver. 

 Escambia County, Alabama (rare). 



Cotypes.Cat. No. 64171. U.S.N.M. 



Genus TREMOTOICHOS Canu and Bassler, 1917. 



1917. Tremotoichos CANU and BASSLER, Synopsis of American Early Tertiary Cbeilostome 

 Bryozoa, Bulletin 96, United States National Museum, p. 59. 



The frontal and the dorsal are tremocysts with sulci. The spiramen opens 

 interiorly at the level of the operculum ; exteriorly it is distant from the peristomice 

 and almost never placed on the median axis of the zooecin. 



Genotype. Tremotoichos rectifurcatum Canu and Bassler, 1917. 



Range. Jacksonian. 



This genus possesses all the characters of Semihaswellia, the difference being 

 little perceptible and consisting solely in the place of the spiramen. As the latter 

 does not appear to exercise the same physiological function (according to Jullien) 

 as in SemihasivcUia we believe it necessary to create a new genus. 



TREMOTOICHOS RECTIFURCATUM Canu and Bassler, 1917. 



Plate 67, figs. 4-23. 



1917. Tremotoichos rectifurcatum CANU and BASSLEB, Synopsis of American Early Tertiary 

 Cheilostome Bryozoa, Bulletin 96, United States National Museum, p. 59, pi. 6, ti. 1. 



Description. The zoarium is free, subcylindrical, branched almost at a right 

 angle. The dorsal is very thick ; deprived of avicularia and formed of a tremocyst 

 with tubules and with sulci. The zooecia are indistinct; the frontal is a tremocyst 

 with sulci placed on an olocyst with very small perforations. The peristome is 

 salient, perpendicular to the zoarial plane, thick, and provided with a small proxi- 

 mal avicularium; the peristomice is orbicular. The spiramen is a pore of the 

 frontal placed on the right or left of the median axis and distant from the pori- 



stomice. 



thpe=0.10mm. n n 



Measurements. Peristomice ) 7 Zooecia. Lz = Q.<0 mm. 



<lpe=0.iOmm. 



Variations. The spiramen is not always apparent (fig. 7) ; it is confused with 

 the tremopores. The peristome of the young zooecia (fig. 5) is thin. The sulci 



