of the Jurassic Bryozoa. 227 



5, Stomatopora intermedia (Miiiist,). 



Aulopora intermedia, Miinster, 1831, in Goldfuss, Petref. Germ. Bd. i. 



p. 218, pi. Ixv. fig. 1. 

 Stomatopora intermedia, Bronn, 1849, Ind. Pal. p. 1202. 

 Alecto intermedia, d'Orbigny, 1850, Prod. Pal. t. ii. p. -lo. 



Diagnosis. — Zoarium forming a crowded network. 

 Zooicia cylindrical, very short. 

 Peristomes raised and much thickened. 

 Distribution. — Corallian, France and Germany. 



Synopsis of Species. 



I. Zooecia regularly tubular. 



Peristomes well raised ; zooecia short dicJiotoma. 



Peristomes slightly raised ; zooecia long Waltoni. 



Peristomes thickened intermedia. 



II. Zooecia pyriform dichotomoides. 



Til. Zooecia hippothoiform Smithi. 



III. Relations of the Jurassic Species. 



The four main characters used in the diagnosis of tliese 

 species are as follows : — The elevation of the peristome [p) ; 

 the shape of the zooecia (c) ; the size, and especially the 

 length, of the zooecia [l) ; and, last and least, the arrange- 

 ment of the zoarium (r). In order to show the relations of 

 these Jurassic species to those of later periods formulee are 

 very convenient. Each of the characters may be represented 

 by a letter, and numbers adopted for the principal variations. 



Thus, let p stand for peristome ; if it is flush it may be 

 indicated by 0, if well raised by 2, and if slightly so by 1. 



In the subjoined formulas the signs denote as follows : — 



