LONSDALE ON EOCENE CORALS FROM N. AMERICA. 



519 



were represented by curved smooth casts nearly on the same 

 level around the stem, in some cases, but in others unequally 

 distributed. The supposed indications of renewals of growth 

 consisted of sharp furrows (a) generally inclined downwards and 

 outwards ; and they were sometimes nearly on the same range 

 around the casts, but they were often disposed obliquely; and they 

 occurred at very irregular intervals. The side branches diverged 

 most frequently at considerable angles, and without any approach 

 to symmetry of arrangement. They were not formed in the 

 slightest degree of pre-existing structures, the component parts of 

 the parent stem being continued persistently upwards ; and there 

 was the same amount of interval between the base of the offset 

 and the cast of the interior of the stem, as between the latter 

 and the ordinary surrounding matrix. The interval was also 

 traversed by filiform processes. There was, however, in general, 

 more or less of irregularity at the point of issue, but without the 

 slightest tendency to such an amount of structural blending, as 

 would authorise the inference that the branch was a subdivisional 

 offset from the parent. 



Localities. — Jacksonboro' ; Eutaw, South Carolina. 



7. Cartophtllia subdichotoma. (sp. n.) 



Main stem cylindrical ; branches numerous, short, slender, very divergent ; 

 outer wall thin, porous, surface finely ribbed and furrowed; lamellae numerous, 

 unequal, very irregular near the periphery ; centre union of lamellae ; branches 

 produced by subdivision of pre-existing structures. 



The specimen preserved in the collection 

 under consideration was of such limited ex- 

 tent that the characters of this coral could 

 be ascertained but very partially. The 

 fossil, however, clearly belonged to the fa- 

 mily Dcedalina of Ehrenberg, the branches 

 arising from a subdivision of previously 

 existing structures ; and of established ge- 

 nera it was most nearly allied to the Ca- 

 ryophyllia of that authority.* There were 

 nevertheless, as stated below, peculiarities 

 in the characters of the branches, and in 



* The Caryophyllia of Ehrenberg is considered by 

 that authority to be equivalent to the Lobophyllia 

 of De Blainville, and the two generic names were 

 probably proposed about the same time (1831 ?). 

 It has, however, been thought advisable to retain 

 the use of the term Caryophyllia as restricted by 

 Ehrenberg, because it includes certain of Lamarck's 

 original species, characterised by the important fea- 

 ture of the branches arising from a perfect subdivi- 

 sional process, and because the Caryophyllia of De 

 Blainville, though also restricted, includes recent 

 and fossil corals of very heterogeneous natures, re- 

 ferable, for the greater part, to other well-distin- 

 guished genera. 



The lower half repre- 

 sents part of a main stem 

 of Caryophyllia subdicho* 

 to?na, and from the trans- 

 versely fractured surface 

 near the centre of the 

 figure, springs a branch 

 composed partly of prolon- 

 gations of the structures 

 constituting the main stem; 

 portions of other branches 

 are shown near a. The 

 upper half exhibits a con- 

 cave cast of the exterior of 

 the coral. (Mag. twice, 

 linear.) 



