182 Descriptions of New, 



frequently expanding laterally and occasionally having a 

 penniform arrangement. The ooecia are very prominent 

 and deeply areolated. They are occasionally crossed by a 

 carina originating at the nearly lunate aperture ; both ridge 

 and opening are, however, frequently absent. 



Family TuBULiPORiDiE. 

 Liripora, n. genus. 



Zoarium crustaceous, growing on a basal lamina. Zooecia 

 not projecting, arranged in single or multiple series, opening 

 along the summits or towards the extremities of ridges 

 which usually more or less radiate from a central point; 

 the intervening grooves without cancelli and covered by a 

 punctate, calcareous membrane. 



The species which I have described as Diastopora lineata 

 and D. fasciculata differ from the true Diastoporce in having 

 the zooecia arranged in uni- or multiserial rows or rictges, 

 and opening either along the summits of these ridges or 

 towards their extremities. The intervening grooves or furrows 

 have no cells or cancelli, but are covered by a more or less 

 punctate, calcareous membrane. These differences necessitate 

 the reference of the two species to a different generic group. 

 I was at first inclined to place them under one of D'Orbigny's 

 fossil genera, such as Actinopora,Discotubigera,Pavotubigera, 

 or Semitubigera, the characters of which are generally 

 essentially the same; but I think it more advisable to give a 

 new name. 



In L. lineata the ridges are frequently very much more 

 elevated than in the specimen originally described and 

 figured, and the zoarium, instead of being circular, is often 

 elongated or irregular in shape. In all these forms the 

 sloping margin of the zoarium, inside the edge of the thin 

 lamina, is occupied by prismatic cells or cancelli, which open 

 all round, and not only opposite the celliferous ridges. The 

 orifices of the zooecia are frequently closed by a punctate 

 membrane. In some specimens of D. fasciculata the ridges 

 and intervening furrows are much more distinct than in that 

 figured. 



Family Discoporellid^. 



Lichenopora Wilsoni, n. sp. Plate I, fig. 5. 



Zoarium discoid, cupped, the basal lamina free and 

 upturned. Centre depressed, reticulated by narrow, rounded, 

 smooth ridges or fibrill83, with narrow^ elongated interspaces. 



