DIASTOPORA. 117 



by the crumpling of the fronds; or may he cylindrical or 

 reteporiforra.) The zoarium is unilaminate or bilaminate. The 

 zocecia are tubular. The peristomes flush, or raised only a 

 small proportion of the length of the zooecia. Goncecia are often 

 present. 



Type species. D. foliacea, Lamouroux. 



Affinities. This genus was founded by Lamouroux, 1 on some 

 fossil species from the Bathonian of Normandy. His diagnosis 

 clearly shows that he included in it both bilaminate and uni- 

 laminate forms. The erectness of the zoarium was, however, 

 clearly an essential character of the genus. Blainville 2 dismem- 

 bered the genus, retaining Diastopora for the unilaminate, and 

 founding Mesenteripora for the bilaminate forms. Many later 

 authors, on the other hand, have enlarged the genus by including 

 in it all the adnate encrusting forms, here regarded as Berenicea. 



Pergens 3 has retained the genus for the unilaminate forms, 

 transferring Bidiastopora and Mesenteripora to the Entalophoridse. 

 He also retains Elea as one of the Melicertitida3. They are, 

 however, all here included as synonyms of Diastopora. The two 

 first are thus placed, as the distinction between unilaminate and 

 bilaminate forms does not appear to me to be of generic value. 

 Elea has generally been taken as founded on Michelin's figures 

 of Diastopora cervicornis (Icon. Zooph. pi. Ivi. fig. 12), but inter- 

 preted according to his figure of Eschara ranvilliana (il. pi. Ivii. 

 fig. 12) and Haime's figure of Diastopora lamellosa (Mem. Soc. 

 geol. France, ser. 2, t. v. pi. ix. fig. Ic). Haime and Pictet, how- 

 ever, recognized that the genus was thus founded only on worn 

 specimens of Diastopora, and with that view I fully concur. 

 Multelea, D'Orb., falls also with Elea. 



In connection with this genus it is necessary to refer to Longe's 

 paper "On the relation of the Escharoid Forms of Oolitic 

 Polyzoa." 4 The discussion in this paper is mainly founded on 

 specimens of Diastopora ; the author concludes by establishing 

 a family DiastoporidaB, including not only such Cyclostomata as 



1 Expos. Meth. (1821) p. 42. 



2 Man. Act. 1834, pp. 430 and 432. 



3 Pergens. Eevision Bry. fig. par D' Orbigny : Bull. Soc. beige Geol. t. iiL 

 Mem. p. 326. 



4 Geol. Mag. 1881, dec. 2, vol. viii. pp. 23-34, pi. ii. 



