4 THE GENUS MONTICULIPORA. 



pendix A, 1845), a memoir which, Hke all the productions of its 

 author, bears ample proof both of conscientious labour and of 

 unusual sagacity and acumen. In this, Mr Lonsdale accurately 

 recognises the chief differences between Chcstetes, Fischer, and 

 the forms which we now group under Monticulipora, D'Orb. — 

 a difference which many subsequent observers were slow to 

 appreciate ; though he erroneously refers to CJicetetes the M. 

 petropolitana of Pander {pp. cit., p. 596). The Stenopora 

 spinigera, Lonsd., and 6". crassa, Lonsd., of the same work 

 (p. 632), are not described or figured with such fulness that it 

 would be possible to arrive at any final decision as to whether 

 they are true Stenoporce, or are really referable to Montictdi- 

 p07'a. As they are of Permian age, the presumption would be 

 that they really belong to Stenopora ; but nothing short of a 

 microscopic examination of actual specimens could settle this 

 point. 



In 1850, as previously stated, the genus Monticiilipora 

 was founded by D'Orbigny (Prodr. de Paleont., t. i. p. 25), 



and four species (viz., vJ/. viainmulata, D'Orb., M. 



ramosa, D'Orb., M. froiidosa, D'Orb., and M. filiasa, 

 D'Orb.) were placed under it. Not only, however, was the 

 generic definition exceedingly vague, but it is to be noted 

 that on the same page of the same work D'Orbigny puts such 

 well-marked types of Alonticidipora as M. petropolitana, Pand., 

 and M. rttgosa, E. and H. (the last being really only a variety 

 of M. raniosa, D'Orb.), under the head of Chcstetes, Fischer. 

 Various other species of Monticnlipora are noted by D'Or- 

 bigny in other parts of the " Prodrome," but they are placed 

 under different genera {Ptilociictya, Ceriopora, Favosites, &c.) 

 It is, moreover, to be remarked, that in the case of the four 

 species above mentioned as placed under Monticidipora, the 

 descriptions, being unaccompanied by figures, are quite insuffi- 

 cient for specific identification, and that their survival at all is 

 really due to the excellent work subsequently done by Milne- 

 Edwards and Haime (Polypiers Fossiles). 



In the same year (1850) as the publication of the genus 



