BRYOZOA. 671 



CYCLOPORA Prout, 1860. 



(Trans. St. Louis Acad. Sci. vol.1, p. 574.) 

 (For generic diagnosis see page 403.) 



The utmost confusion has hitherto prevailed among palaeon- 

 tologists who have sought to determine the true characters of 

 this genus. Such a condition of affairs appears natural enough, 

 when we consider that according to Prout's description the 

 principal feature of the genus is the concentrically and radiallv 

 striated epithecal membrane ("sole"). The zooecia are said by 

 him to be sub-tubular, sub-prismatic, and separated by a po- 

 rous interstitial net-work. The last character in conjunction 

 with the preceding, suggests Fistulipora, but, when we examine 

 his species, none of them show anything like the interstitial 

 net-work of that genus. On the contrar}-. none of his original 

 species, excepting C. fungia. which, being the first described, I 

 regard as the type, have any interstitial cells whatever. C. fiin- 

 pia too, when normally developed, has only a depressed space 

 back of the zocecia aperture, which as growth proceeds is grad- 

 ually drawn out into a tabulated mesopore. Four species are 

 described by Prout, and these in themselves already show how 

 extremely misleading an index to generic affinity is the com- 

 mon possession of a striated epitheca. Thus C. discoidea differs 

 so much from C. fungia in its zooecial features that I propose 

 the new genus Proutella for it; C. polymorpha is a true Steno- 

 pora, and probably identical with his Flustra tuberculata; and 

 C. jamesi is the same as Ptilodictya pavonia D'Orb. 



The genus as now defined is based upon specimens that were 

 identified by Dr. Prout himself with his C. fungia. It is still 

 somewhat unsatisfactory, and much more work is necessary 

 before the true position of the genus can be established. 



CYCLOPORA FUNGIA Prout. 



PL LXVm, figs. 3-3e. 



Cydopora fungia Prout, 1860. Trans. St. 'Louis Acad. Sci. vol. 1, p. 577. 

 Cyclopora fungia Prout, 1866. Geol. Surv. HI. vol. n, p. 419, PL 22, flgs. 9-9b. 



Zoarium an irregularly undulating sub-circular expansion, 3 

 mm. or less in thickness, and from 2 to 7 cms. wide. Under 



