25 



as the subopercular area and takes up the whole breadth of the zooeciuin in its distal 

 part is provided with a strongly developed, as a rule angularly bent oral ledge, the 

 height of which in its distal part may be contained about three times in the height 

 of the whole aperture. The form of the latter varies between half-elliptical and 

 roundedly triangular, the lateral margins being in their proximal half sometimes 

 almost parallel sometimes more or less converging distally. The peristomial thick- 

 ening is rarely distinctly developed being in most cases coalesced with the convex 

 subopercular areas of the adjacent zooecia, and the apertures of the zooecia in the 

 same transverse series are in most cases divided by columnar projections formed 

 wholly or partly by the lateral parts of the peristomial thickening. The proximal 

 part of the peristome forms a more or less prominent lip. The operculum is very 

 convex, but in such a manner that its proximal half is provided with a triangular flat, 

 obliquely ascending area from the margins of which the surrrounding parts are 

 gradually descending. It is provided with distinct radiating striae. 



The Heferozooecia which are about half as long as the zooecia are spar- 

 ingly spread over the surface of the colony, singly or in pairs, the two hetero- 

 zooecia belonging to a pair being either placed side by side or divided from each 

 other by a single zooecium. The strongly projecting obliquely ascending aperture 

 is as long as broad or a little longer and has a somewhat variable form, the two 

 lateral margins being more or less converging distally. No »lateral processes*. 



Ooecia have been found. 



No Kenozooecia. 



The Closure takes place by means of a concave or in most cases flat lamina 

 which arises a little within the free edge of the oral ledge from which, therefore, 

 il is distinctly defined. A similar closure I have seen also in a hcterozooecium. 



The Regeneration. I have seen cases of regeneration both of zooecia and of 

 heterozooecia. 



The Colonies are free, with cylindrical branches, and in some of the fragments 

 examined I have found superficial layers. 



Mel. semiluna is nearly related to Mel. angulosa and may perhaps be regarded 

 as a constant variety of this species, from which it is most easily discerned by the 

 lack of or the feeble development of the marginal ridges and the tubercles, the form 

 of the operculum and the mode of closure. I have seen a number of fragments 

 from Bruille-Ponce (Turonian). 



Meliceritites palpehrosa nov. nom. 



Melicertites semiluna d'Orbigny, Bryoz. cret. p. 623, pi. 736, fig. 20 — 21. 

 noil — — Gregory, Cretac-Bryoz. p. 343. 



(PI. Vll, figs. 1—9.) 



The Zooecia are chiefly represented by their large half-elliptical apertures which 

 as a rule take up most of the surface of the colony. Marginal ridges and tubercles 



D K. I). Vidensk. Selsk. Skr., 7. Kiukke, ti,Tturvideiisk. oti matheiii. Afci. \ I. 4 



