346 Mr. H. J. Carter on Stromatopora clartingtoniensis. 



Stromatopora darting toniens is , n. sp. 

 (PI. XVIII. figs. 1-5.) 



Coral massive (PL XVIII. fig. 2) or spreading over 

 foreign objects (fig. 1) ; the latter form presenting a reticu- 

 lated surface which is more or less grooved throughout by 

 branches of the astrorhiza, that radiate respectively from more 

 or less convex elevations, whose summits, from weathering, 

 may present one or more apertures (fig. 1, ccc) ; mutatis 

 mutandis, like the growing surfaces of Millepora alcicornis 

 and Hydractinia arborescens, &c. Showing in the vertical 

 section (fig. 4) that the basal structure or ccenenchyma is com- 

 posed of rectilinear latticework, arranged in concentric, more 

 or less undulating laminae, traversed by the branches of the 

 astrorhiza (fig. 4, d,ee); and in the horizontal section (fig. 5) 

 a union of the ends of the perpendicular rods by intervening 

 fibre, which presents a curvilinear or quasi- vermicular form, 

 still traversed by the branches of the astrorhiza, but now seen 

 from a horizontal point of view instead of laterally, whereby 

 the branch is more or less observed to ramify among 

 the ccenenchyma (fig. 5, e), until, by subdivision, it finally 

 becomes confluent with the vermiculated ccenosarcal cana- 

 liculi, with which, too, it is also in communication laterally 

 throughout its whole course. Astrorhiza consisting of a 

 group of radiating branches, which dip downwards from a 

 vertical axis to ramify on all sides among the laminated 

 ccenenchyma until they are lost by subdivision in the cana- 

 liculi of the ccenosarc, as just stated (fig. 1, c c c and b } e, yg } 

 also fig. 4, d, and fig. 5, e, &c.) ; parting from the axis succes- 

 sively (fig. 1, e,f) stolon-like, without any distinctly continu- 

 ous vertical canal or stem ; the larger branches traversed here 

 and there by tabular, inequidistant, direct or oblique (fig. 3, a). 

 Centres of the astrorhiza? at different distances from each other, 

 varying from |-1 inch in the massive form (fig. 2, a a a a) , 

 but much wider apart in the incrusting one (fig. 1, ccc), 

 where the branches are sometimes 2 inches long and l-24th 

 inch wide near the centre. Size variable. 

 Hab. Marine. 



hoc. Devonian Limestone. Pit-Park Quarry, Dartington, 

 near Totnes. 



Obs. It is not improbable that fig. 1 represents the true 

 surface of the incrusting form, but so altered by weathering 

 and decomposition that it presents nothing satisfactory beyond 

 the large size of the astrorhiza? ; while in. fig. 2 the branches 

 of the astrorhiza? are necessarily represented as truncate, from 

 their ultimate ramifications being below the plane of fracture. 

 In the vertical section of the ccenenchyma (fig. 4) the lines of 



