309 



the operculum connected with the hinge-teeth is directed towards the growing 

 margin of the colony. The separating walls, which are all single, are provided 

 with small, uniporous rosette-plates, and the length of the frontal surfaces, which 

 are not distinctly marked off from the surface of the colony, is considerable less 

 than the depth of the zooecia. Immediately distally to each zooecial aperture there 

 is a pore which leads into a cavity in the frontal wall. Dependent avicularia 

 appear in all the species and in most of them peculiar, likewise dependent keno- 

 zocecia of unknown significance, lunoecia, the frontal wall of which is provided 

 with a crescent-shaped slit. Freely projecting, helmet-shaped ooecia may appear, 

 which seemed to be formed by a single calcareous layer and to have no covering 

 membrane. They arise from the distal part of the peristome and may provision- 

 ally be called peristomial. 



The colonies in the hitherto found species are free, either laminate, with the 

 zooecia arranged in two layers or they have the form of a low cone or arched 

 disc, the arched surface of which is formed by a layer of zooecia, whilst the inner 

 and basal surfaces are formed by avicularia arranged in layers. 



Whitelegge* who has given a synopsis of the hitherto known species ex- 

 presses the supposition in his short paper, that a closer examination of these 

 forms will lead to a new family being formed for them, and although one of the 

 main reasons of the author for this supposition is based upon inaccurate examin- 

 ation, his conclusion is quite correct. Among the characters given in the above 

 diagnosis he lays stress on the presence of the peculiar pore and the quite ex- 

 ceptional orientation of the zooecia. 



The characteristic kenozooecia, for which we propose here the name »lunoecia« 

 (PI. XXIII, figs. 7 a, 7 b, PI. XXIV, fig. 1 a), are like the frontal avicularia small, 

 dependent chambers, each of which is connected with a zooecium by means of a 

 uniporous rosette-plate. Their frontal surface is provided with a crescent-shaped 

 slit with the convexity turned inwards towards the centre of the colony. Further, 

 these lunoecia, concerning the significance of which I can offer no definite opinion, 

 occur in somewhat small numbers and are found both in the oldest and the 

 youngest parts of the colony. Their position with regard to and connection with 

 the zooecia are most readily understood when we grind down the flat basal part 

 of the colony in one of the more flatly arched species, e. g. Conescharellina phil- 

 ippensis (PI. XXIV, fig. 1 a). W^e then readily see that both the lunoecia as well 

 as the avicularia are separated by a wall from the zooecia and that this wall is 

 provided with a uniporous rosette-plate. Further, all these superficial chambers 



' 117, 



