2Q rROCEEDIXGS OF THE GEOIOftlCAL SOCIETY. [NoV. 21, 



allied to Se_ptastrcea IIaimei,'Wngh.t, sp., of Street ; for the genus may 

 readily be mistaken in sucli a cast as that from which the species /S, 

 hasaltiformis was determined. 



Our White Lias has produced three species of Bi\miQ{\. Montlivaltioi: 

 not one of them is accurately determinable ; but the outsides of the 

 forms are rugged and ridged. 



As yet only one species has been found in the British Avicula- 

 contorta zone, namely a Montlivaltia with five cycles of septa, but 

 apparently indeterminable specificallj'' ; and the Ehsetic beds of Prance 

 and the Duchy of Luxembourg have not yielded a single form. 



Avery diiferent state of things occurs inLombardy, where the coral- 

 fauna of the formation of Azzarola almost rivals that of Brocastle in 

 its number of species, but far surpasses it in the extent of its area*. 



Associated with a great molluscan fauna peculiar to the formation, 

 and with many species of shells common to other strata, and situated 

 low down in the Infra-Lias, is a very interesting series of Madrepo- 

 raria, which has a decidedly Infra-liassic facies and is not very de- 

 ficient in Triassic types. 



The Madrepore-bed, as it is termed by Stoppani, is seen above the 

 Azzarola beds with Cardium Kliceticum, Myophoria injlata, Mytilus 

 Psilonoti, Avicula contorta, Terehratula gregaria, &c. wherever the suc- 

 cession of the rocks can be made out, either on the south-east slopes 

 of the Alps, as on the Lake of Como, or on the north-west slopes 

 to the south of the Lake of Geneva. The Madrepore bed is described, 

 moreover, as occurring below and in the midst of the Azzarola beds, 

 and as forming a dense layer of 8 or 10 yards in thickness. The 

 prevailing species is a branching form called Bhaodopliyllia Lango- 

 hardica. M. Stoppani describes many species from this bed, and has 

 had his types carefully drawn. Without any disrespect for his 

 opinion, I have suppressed 12 of his species on account of their 

 having been founded on casts of corals, whose generic determination 

 even is hardly possible. It would appear that his genera Lepiconus 

 acid Pyocidopliyllum are described from casts of Montlivaltice and 

 Tliecosmilice, whose original hard parts have been dissolved away. 

 Two of his species of Stylina are taken from casts ; and the figures of 

 them greatly resemble the casts of Astroccenia gibhosa,w\n.Q\i are com- 

 mon enough in the Sutton Stone. A Cyatliophyllum he describes 

 is clearly a fragment of a long Montlivaltia, and the TrocJiocyatlius 

 has none of the essential characteristics of the genus as established 

 by its founder. The BhaMopliyllice, if they can be permitted 

 to remain in that genus, are the most important species ; they re- 

 semble in their habit of growth many ThecosmilicB, and form great 

 masses of tangle, like Tliecosmilia Martini of the Cote d'Or and 

 the Thecosmilice of Cowbridge and Brocastle. 



The following are the species selected from M. Stoppani's studies: — ■ 



Rhabdopliyllia Sella. 



■ Langobardica. 



Menighini. 



' de Filippi. 



Montlivaltia Gastaldi. 



Stylina Savii. 

 Thamnastroea Batarra?. 



Escheri. 



Meriani. 



rectilamellosa {Winkl.). 



Stoppani, Monog. des. foss. de 1' Azzarola. 



