134 LOWER PENINSULA. 



VESICULARIA, N. Genus. 



Compound polyparia formed of a superimposed series of calycinal 

 cups, of coarsely blistered surface, which in vertical sections appear 

 as a uniform succession of layers of large, unequal, vesiculose 

 plates, perfectly resembling a vertical section through a Cysti- 

 phyllum. These blistered calycinal membranous layers are radiated 

 by plications, which are linear low crests in the circumference of 

 an inner, broad, shallow cell pit, the bottom of which is occupied by 

 a flat diaphragm, over which the crests converge toward the centre, 

 gradually vanishing. The margins of the cells are broad, expanded, 

 and confluent with each other, without demarkation. The radial 

 plications lose, in their divergence across them, the crested form, 

 and expand into flattened, gradually widening bands, as in Chono- 

 phyllum. 



The crest-like portion of the plications in the circumference of 

 the inner cell pit forms, by combination with the invaginated series 

 of cups, a narrow cycle of vertical crests surrounding an inner core 

 formed of diaphragms. In the outer area no trace of continuous 

 vertical leaves is noticeable. Vesicularia is closely related with 

 Strombodes ; it differs from it in its broad calycinal bottoms having 

 the shape of diaphragms, and in a prevailing disposition of all the 

 calycinal layers to a vesiculose blistered structure, which in the 

 other genus is only periodically so, and alternates with homogene- 

 ously formed laminar layers of more highly finished surface. From 

 Chonophyllum it is likewise distinguished by the vesiculose struc- 

 ture of the superimposed cup walls ; from Cystiphyllum it only 

 differs in having a compound mode of growth with confluent cells. 



VESICULARIA MAJOR, N. Sr. 



Discoid expansions formed of large confluent polyp cells. Calyces 

 shallow,'explanate, with a broad, dish-shaped central pit, the bot- 

 tom of which is formed by a flat diaphragm. Radial plications 



