26 Mr. H. M. Bernard on (he 



With the striking superficial resemblance to Cyathophyllidas 

 to mislead him, it is no wonder that Mr. Quelch was misled. 

 Nor do I see how his claim could have been disproved without 

 a clear understanding- of the position of the prototheca in 

 coral morphology. 



While on this subject I may point out that Mr. Quelch's 

 figure (7. c. pi. xii. no. 5) of a small calicle of Moseleya 

 showing marked tetrameral symmetry is seen on the actual 

 specimen to have been distorted by too close contact with the 

 shell of a mollusk much larger than itself. Its internal 

 arrangement is not quite normal. Mr. Pace has presented 

 the Museum with over a dozen specimens, most of them 

 single forms in all stages of growth, and not one shows any 

 such striking tetrameral arrangement. On this subject of 

 tetrameral symmetry in the so-called " llugose " division of 

 the Madreporaria I would refer the reader to what is said 

 above (p. 11). 



Whether, after all, the subsequent classification of the 

 Lithophyllidce will ultimately admit of the existence of a 

 genus Mostlcya among them I cannot say. In this paper I 

 am only concerned in showing that it has no place among 

 the Cyathophyllidae. The latter are characterized by extreme 

 simplicity of protothecal modification, the Lithophyllidaj by 

 great complexity ; they are at opposite ends of the evolution 

 of the coral skeleton. 



Before closing this section I should like to refer onee more 

 to the difference between the principles of modifying the 

 prototheca shown in diagram tig. 13 h and diagram fig. 15. 

 Jn both the soft parts bag over and reach the ground, but in 

 the former the lip grows with the growing of the soft parts 

 and its bend is a true bend. In fig. 15 the soft pints seem 

 to overflow the edge of the cup too rapidly actually to bend 

 the edge. Only alter they have taken up their new position 

 do they secrete a layer on the outer side of the cup, and this 

 layer is practically the homologue of the bent-down edge 

 shown in fig. 13 h. The two methods are thus clearly 

 distinct, but it is not always easy to say whether a particular 

 case belongs to the one or to the other. For instance, in those 

 specimens of Lithophyllim in the Museum which have the 

 coralhtes crowded together and forming pseudo-colonies, it is 

 frequently noted that where the interseptal beuli of adjacent 

 corals run into one another the dissepiments are everywhere 

 arched, suggesting an open bend of the thecal lip, such as is 

 shown in the diagram fig. 13 h, or even more resembling the 

 bend of fig. 13 g, or even of 13/. But in the specimens with 

 single corallitcs the actual lip of the theca is mo3tly a solid plate 



