DESCRIPTION OF CHALK CORALS. 307 
Believing that on the grounds stated above, the fossil is not admissible into 
any established genus known to the author, the designation Homeosolen is pro- 
posed for it, in allusion to the composition (onoto¢ similis, cwArw tubus). 
Homeosolen, n. g. 
Tubular, fixed, tubes of two sorts—one large for the viscera, the other small— 
variously intermingled, both inclined in the same direction, partially visible on 
the surface, or wholly concealed, limited to one side of the coral ; mouths simple 
tubular extremities ; back without pores, composed of a continuous lamina. 
Homeosolen ramulosus. (Tab. XVIII. B. figs. 3, 4 & 5.) 
Branched, lateral shoots numerous, variable in extent, sometimes rudimentary ; 
rarely if ever anastomosed ; apertures to large tubes disposed longitudinally along 
the centre of branches, generally in transverse rows adjacent to the sides; second- 
ary openings varying in number according to amount of interspace, most nume- 
rous on perfected sides and in axillze of branches ; exposed portion of each set 
of tubes inclined upwards or against the branch ; when perfect semicylindrical ; 
within the branches and on the sides inclined more or less towards the surface ; 
reverse side, a thin lamina variously ridged. 
Eight specimens of different dimensions were examined. Two of them, obli- 
gingly lent by Mr. Bowerbank, are represented by figures 3, 4, and the remaining 
six belonged to Mr. Dixon’s cabinet. Some differences of character not wholly 
assignable to opposite surfaces are visible in those figures, the breadth of the 
branches being chiefly dissimilar, also the length as well as the number of the 
lateral shoots; and as they distinguished the whole of Mr. Dixon’s series, 
they ought therefore apparently to be regarded as belonging to the normal con- 
dition of the coral. In those specimens the minor pores were likewise generally 
less numerous than in the example figure 3. Nevertheless no differences con- 
sidered of sufficient importance to warrant specific separations were observed ; 
and one specimen in Mr. Dixon’s collection, which gave a front view, presented 
an approximate thickness in the main stems. ‘The little example (fig. 5) is more- 
over believed to exhibit only a young condition, the visceral and other tubes 
having full dimensions ; and the small intervals for increase of breadth in the 
branches are not very different from those which existed in the large specimen 
figure 4, where the stems at the lowest extremity are aggregated and partially 
united so far as the back lamina is concerned, though elsewhere a want of ana- 
stomosis is apparent. 
