358 W. Lonsdale on Tertiary Corals from the United States. 



Mr 



greement, a reader would infer 



that I had totally overlooked them. In Dendrophyllia ramea ) 

 a certain but limited connexion apparently exists, for a time at 

 least, between the animal matter which occupies the interior of a 

 stem or branch, and that which invests it. The great thickening 

 of the coral, however, is effected by means of the mantle which 

 covers the exterior and forms more or less concentric layers. 

 This mantle often extends also over portions of an adjacent branch, 

 which had, apparently, been deprived of vitality, and deposits ad- 

 ditional layers on that branch. In such cases, there could be no 

 connexion between the mantle and interior of the encrusted 

 branch. This process Mr. Dana expressly alludes to in p. 385 of 

 his work. No concentric depositions are visible in the sections 

 of specimens No. 2, and it was with reference to the successive 

 layers formed on the surface of Dendrophyllia by the external 

 mantle ; and the evidence in the Alabama coral of a totally differ- 

 ent operation, that the term Endopachys was adopted, certain 

 structural agreements having been shown to exist between the 

 two genera. 



I hope this explanation if clear will vindicate rne from having 

 inconsiderately named your coral. 



Madrepora tubulata, Mr. Dana says, " is an Oculina," p. 221. 

 Your specimens had only twelve lamellae.* Oculinae have more 

 than twelve. Madreporae have only twelve. This structural dis- 

 tinction is very generally accepted. Internally the American coral 

 agreed far more closely with Madrepora than Oculina, so far as its 

 state of preservation warranted an opinion. The chief objection 

 to the generic assignment is in the mode of developing additional 

 abdominal cavities, and this was felt at the time ; but not men- 

 tioned because I was not certain that that process was universal 

 throughout the genus. Mr. Dana in his work, p. 486, received 

 long after the notice was printed, describes three species of auor 

 repora, in which the normal process is apparently deviated from. 

 On this, however, I would not for a moment rest as a justification. 

 I named the coral after a careful examination of the im F rt h eC d 

 evidence before me, and placed it in the newest, allied, establish 



genus, the specimens 



The reply to the critic might be : It is not an Oculina. ^ 



Columnaria ? sexradiata. — The note of interrogation shou 

 not have been omitted by Mr. Dana. It is statedf that the tos 

 is allied to Astrcea calicularis, and Mr. Dana in his description 

 the latter, refers to Esper, pi, 16, Fig. 12. The coral there r £ 

 resented, is generically if not specifically allied to the fane z ^ 

 phyte you kindly gave me, and is labelled " Caryophylha— 1 

 Lieut. Holland, Prince's Island, west coast of Africa n 



* See notice, Geological Journal, vol. i, p. 520. 

 t Silhman's Journal, p. 221. 



