New Lower Silurian Bryozoa. 



177 



MITOCLEiMA? MUNDULUM, n. sp. 



Fig. ■l.—Mitoch ma .' mundulum, n. sp. a and b. two bifurcating fragments of this 

 species, natural size, and x'.». c, one of them xl8. 



Zoarium ramose, very small, the branches 0.5 or 0.6 mm. in 

 diameter, with faint transverse stride or wrinkles over the spaces 

 between the zooecia. The latter are tubular, with their apertures 

 projecting strongly upward and outward, and not appreciably 

 constricted. Diameter of protruding portion of zocecium about 

 o. 15 mm. 



The interior of this species has not yet been determined because 

 of the absence of specimens suitable for slicing. The generic 

 position is therefore somewhat questionable, since it may prove to 

 have the structure of Diploclema, Ulr., a genus including, externally, 

 very similar forms. 



Position and locality : Top of Trenton Shales, at Cannon Falls, 

 Minn. 



diastoporina, n. gen. 



Zoarium bifoliate flabellate, resembling Diastopora. Zocecia 

 tubular, prostrate, not entirely immersed. Apertures constricted 

 oblique, the anterior side not elevated. Interpaces striated. Type, 

 D. flabellata, n. sp. 



