No. 1797. 



NEW TVBULIPOROID BRY0Z0A—BA88LER. 



499 



for them. Thus, while the typical forms of Stomatopora have zocEcia 

 with more or less parallel sides and no narrow, elongated, proximal 

 portion, and large, open, exsert apertures, the new genus comprises 

 the uniserial, adnate tubuliporoids in which the individual zooscia 

 are contracted at their proximal end and rounded at the distal or 

 apertural portion. The latter type of structure pertains to species 

 ranging from the base of the Ordovician to the close of the Mesozoic, 

 and the known representatives are divisible into no less than sixteen 

 species. Considering these facts and also that the species are always 

 easily distinguished from the typical forms of Stomatopora, I propose 

 for them the new name Corynotrypa, in reference to the club-shaped 



Fig. 1.— Genotypes of Stomatopora and Coeynotrypa, illustrating generic differences. 

 0, Stomatopora DicHOTOMA. Jurassic, Hampton Cliffs, England. (After Haime.) 6, Cory- 

 notrypa DELICATULA. UPPER ORDOVICIAN, CINCINNATI, OHIO. (AFTER UlEICH.) 



zocecium with the perforation or zooecial aperture at its swollen end. 

 The differences between the genus Stoinatopora as thus restricted 

 and the new genus Corynotrypa are brought out in figure 1. 



TERMINOLOGY. 



On account of the great simplicity of the clavate zooecia, and the 

 constant difficulty in discriminating closely allied forms, it has been 

 found useful to employ the following terms in their descriptions. The 

 slender, proximal portion (s) of the zooecium (figure2),'*is seen to vary 



« All of the original illustrations in this paper have been prepared by Miss Frances 

 Wieser from camera lucicla sketches drawn by the author. Great care has been taken 

 to secure exactness of measurement, especially in the angle of divergence. When- 

 ever a specimen did not show its characters clearly under the microscope, it was 

 whitened by one of the several processes employed for this purpose. A thin coat of 

 some white substance applied to apparently indistinct specimens often brings out 

 their structure with astonishing clearness. 



