296 Geological Society. 



were described. They were referred to eight species of Zaphrentis 

 (two being, perhaps, rather referable to AmpleMus), one of Campo- 

 plitjUmn (?), oue of Lophopliijllum (?), one of Amplexus, and one of 

 Cyatliopliyllum i^l). The Amplexus was identified with A. tor- 

 tuosus, Phillips ; two species of Zaphrentis were provisionally named 

 Z. calceoloides and Z. suhgigantea (the last being possibly a form of 

 Z. gigantea, Lesueur) ; and for the Cyathophyllam the name 0. hi- 

 laterale was suggested. For the remaining forms no specific names 

 were proposed. 



It was shown that the genus Zaphrentis is better represented in 

 British Devonian beds than had hitherto been supposed. At the 

 same time some corals exhibiting bilateral symmetry, and which the 

 author himself had at first taken for Zaphrentidce, belong to other 

 families. It was shown that the corals of the family iu question are 

 distinguished by successive complete floors, well-defined septal cha- 

 racters, notably the discontinuity of the septa as vertical plates where 

 arrested by the floors, the rudimentary condition of the secondary 

 septa, the almost complete absence of vesicular endotheca, and, 

 lastly, the septal fossula and other signs, internal and external, of 

 bilateral or, more rarely, quadripartite symmetry. 



2. " On the Internal Structure of Micrahacia coronula, Goldf., 

 sp., and its Classiflcatory Position." By Prof. P. Martin Duncan, 

 M.B. (Lond.), F.R.S., F.G.S. 



Fangia coronula, Goldf., a characteristic newer Greensand Coral, 

 found at Warminster and near Dunstable in England, and in the 

 beds of Essen and Le Mans, is the type of the genus Micrahacia of 

 Milne-Edwards and Haime, and the external characters have been 

 carefully and accurately described by those authors. They placed 

 the genus in the family of Aporose Corals called Fungida? by Dana, 

 and in the subfamily Funginae, near the genus Fangia (as restricted 

 by Dana). 



The author finds that the internal structure of Micrahacia coronula, 

 which he has examined carefully, confirms MM. Milne-Edwards 

 and Haime's view of the classiflcatory relations of this species. 

 After describing the characters of the base, costae, septa, and synap- 

 ticuloe in detail, he finds that there is no theca or true wall. He 

 gives the following amended description of the genus Micrahacia. 

 Corallum simple, lenticular, convex above, slightly hollowed out 

 below, resting on the edge of the basal disk. Costa? delicate, simply 

 granular, bifurcating at the calicular margin. Intercostal spaces 

 crossed by synapticuljje, and having a regular series of openings 

 leading upwards into the interseptal loculi. Septa continuous with 

 the intercostal spaces, and formed by the junction of a process from 

 the two nearest costae, arched, denticulate, solid, unequal. Synap- 

 ticulse well developed in series, continuous or discontinuous, termi- 

 nating moderately high up on the interrupted loculi, and ending as 

 intercostal bars having canal-like spaces between thera. Coluraella 

 rudimentary. 



