356 ZOOPHYTES. 



of the middle is transversely septate, while either side of this medial 

 portion the texture is cellular. In some species the cellular portion 

 is very narrow, and these form a transition to the genus Calophyllum; 

 this texture will in all instances be perceived on polishing down the 

 exterior, when the surface will appear, as described, angulately cel- 

 lular. The transverse septa are occasionally much convex above. 



In the dianthus, the intermediate dissepiments run obliquely from 

 above downward and inward ; and the same is true of many other 

 species. There are others in which these dissepiments run upward 

 and inward, as represented in plate 26, figures 3, 4, 4 a ; and as the 

 species have also some difference of habit, they constitute at least a 

 subgenus, if not a wholly distinct group. The name HELTOPHYLLUM, 

 has been applied by Mr. James Hall to a specimen of this kind in his 

 cabinet, and may well be retained. It is represented in his N. Y. 

 Geological Report, fig. 3, p. 209, and is probably near the Cyatho- 

 phyllum Helianthoides of Goldfuss, plate 20, fig. 2. 



The subgenus Heliophyllum will then contain species having gene- 

 rally the transverse septa of the Cyathophylla, but with the interme : 

 diate dissepiments running oblique upward and inward. Plate 26, 

 figure 3, is a section of part of the same turbinate species, figured by 

 Mr. Hall ; arid figs. 4, 4 a, are views of sections of a massive Astraeoid 

 species. 



Both solid, ramose, and simple species, are included among the 

 Cyathophylla; and we do not deem it necessary to separate the cylin- 

 drical and prismatic species, which have a similar internal texture, 

 although heretofore referred in part to the genera, Lithodendron, Co- 

 lumnaria, and Caryophyllia. Should they be separated, a new genus 

 should be constituted, as they are not true CaryophylliaB, nor Colum- 

 naria? ; neither do they belong to the Lithodendrum of Schweigger. 



GENUS II. CALOPHYLLUM. DANA. 



Caryophyllida simplicissima, caliculato-ramosce, aut aggregates. Coral- 

 lum penitus transverse septatum, cellis simpliciter concavis, regulariter 

 stellatis; intermediis dissepimentis nullis, itaque laterum texturu non 

 cellulosa. 



