12J ^Iv. AV. S. Kont on a neio Genus of M.i'Jrepopni'ia. 



])Ower ot" the coiupouiul inicroscdpi*, liowevcr, beiui? requisite 

 to deiine its hirsute character, 'J'he auipulhe, thougli sparin^ii-ly 

 scattered, arc occasionally nearly globuhxr, aiul of a size almost 

 equalling in diameter that of the ramuscules which support 

 them. 



Mr. Johnson, in deseril)ing tiie species as AUopora made- 

 rensis, considers it to j)ossess a great general resemblance to 

 Sfi/Iasfej' f/ahelfifornn's, and, being under the impression that 

 it does not possess auipulUe, is of the opinion tliat this last 

 circumstance indicates that the two genera AUopora and 

 Stylaster should be united. Admitting the insufficiency of 

 the presence or absence of these episclerenchymatous develop- 

 ments as a generic or even specific diagnostic (which fact 

 I shall amply demonstrate in describing some new species of 

 AUojwra ])roper in a forthcoming catalogue of tlie ^ladreporcs 

 contained in the British Museum, now in course of publication), 

 the alternate-distichal or entirely irregular nature of the gem- 

 mation which obtains in the two respective genera is alone an 

 all-sufficient line of demarcation ; and accordingly, of these 

 two, Mr. Johnson's species is the more closely allied to Sty- 

 laster. 



Mr. Johnson, again, suggests that this species may possibly 

 be identical with the AUopora infundihidifera of Lamarck. 

 Specimens of the last-named species in the National collection, 

 however, prove it to be very distinct from that interesting 

 form. 



With regard to the true zoological affinities of Steno/ielia, 

 the pedunculated and transversely ovate caliccs all turning 

 the same way, and the suUlichotomous mode of gemmation 

 frequently evinced, seem rather to indicate its close relation- 

 ship to Cri/ptohelia of the West-African coast ; it is, moreover, 

 a remarkable and significant fact that in many instances the 

 lower half of the calyx is as it were thrust in upon the calicinal 

 fossa ; and this may be accepted as a disposition towards the 

 extreme modification in the same region which obtains in that 

 genus, where we find that the inferior half is folded back so as 

 to entirely conceal the ealicular fossa. The close proximity of 

 the habitats whence these two genera have been procured also 

 carries with it a highly important significance. 



The genus Endohelia of Milne-Edwards may possibly form 

 the immediate intervening link connecting the two genera 

 here compared. It is distinguished l)y having the inferior 

 edge of the ealices developed in a tongue-like form in front of 

 the orifices, though to a less extent than in Crr/ptoheJia ; the 

 surface of the ccenenchyma is smooth, and both columella 

 and pali arc deficient. 



