434 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Occurrence. Vicksburgian (Marianna limestone) : West bank of Conecuh 

 River, Escambia County, Alabama (very common) ; near Claiborne, Monroe 

 County, Alabama (rare).' 



Cotypes. Cat. No. 62593, U.S.N.M. 



Genus ENOPLOSTOMELLA Canu and Bassler, 1917. 



1917. Enoplostomella CANU and BASSLER, Synopsis of American Early Tertiary Cheilostome 

 Bryozoa Bulletin 96, United States National Museum, p. 46. 



The apertura and peristomice of the ovicelled zooecia are identical with the 

 apertura and with the peristomice of the ordinary zooecia. The frontal is a 

 tremocyst with wide-mouthed tubules. The ovicell does not entirely surround the 

 peristomice. There is an avicularium in the peristomie in the immediate vicinity 

 of the peristomice. 



Genotype. Enoplostomella defixa Canu and Bassler. 1917. 



Range. Jacksonian, Vicksburgian. 



ENOPLOSTOMELLA SYNTHETICA, new species. 



Plate 90, figs. 1-9. 



Description. The zoarium is free, formed of from 2 to 4 lamellae, back to 

 back, and separable. The zooecia are indistinct and irregular (exteriorly) ; the 

 frontal is formed of a tremocyst with very large wide-mouthed tubules superposed 

 on a thin olocyst perforated with small pores. The apertura (in the interior) is 

 semihmar with a concave proximal border; the peristomie is very deep; the 

 peristomice is orbicular, imbedded, with a wide and short rimule-spiramen limited 

 by the peristomial avicularium. The ovicell is hyperstomial, much imbedded, little 

 salient covered also with large tremocystal pores ; it opens into the peristomie. In 

 each peristomie there is a small triangular avicularium, little visible externally. 

 On the frontal, laterally a small or very large avicularium is formed by the 

 coalescence of the tubules. 



Measurements. Apertura Iha 0.15-0.17 mm. . fZz=0.80-0.90mm. 



(interior) Uz=0.16 mm. La 123=0.35-0.50 mm. 



Variations. The function and transformation of the tubules give to this 

 species a disconcerting aspect of irregularity, augmented still more by the orienta- 

 tion of the zooecia, which is not constant (figs. 2, 3). The interior aspect (figs. 

 4, 5, 8) shows, on the contrary, a more simple organization. Through the thinness 

 of the olocyst, perforated with small pores, the tubules regularly placed in 

 quincunx can be seen ; the frontal avicularium is visible only if it is very large. 



The development of the buds of the endocyst and the result of their coalescence 

 form here a very remarkable synthesis. The ,buds. revealed by the very similar 

 openings of the olocyst become transformed into adventitious organs more or less 

 complicated, which engender small simple avicularia with pivot, some avicularian 

 cavities and large avicularia with or without pivot, in which the mandibles ought 



