18 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



of Madrepora of Esper. There are six species enumerated by- 

 Messrs. Ed. and Haime, viz., D. cristagalli, Ehenb., D. Gumingi, 

 E. and H., D. costatum, D. diantlius^ Esper., D ? StoJcesii, E. and 

 H., and D. taurinense, Michelin. The latter is fossil. Prof. 

 Duncan has reduced the four first to mere varieties of one species, 

 for which he retains the name of B. cristagalli, though it seems 

 as if Esper's name (D. dianthus) should be the one selected, as it 

 has long priority (1797). The same author regards D. Stolcesii 

 as an immature form of the other varieties. He says (Madre- 

 poraria of the deep sea; Trans. Zool. Soc. vol. 8, 1873, p. 321). 

 " If the variations of the typical form of this species are studied, it 

 will be noticed that there are great difference in the position, 

 size, and continuance of the costae, in the exsertness and granula- 

 tion of the septa, in the height, compressedness, and size of the 

 base of the corallum, and in the granular ornamentation of the 

 outside of the wall in different specimens. The size, costal 

 developement and granular condition of the ornamentation of the 

 septa, and outside of the corallum, depend upon the age and 

 nutrition of the specimen. Very thin septa are not so granular 

 superiorly as those of corals, which have very thick walls, and 

 dense septa, and the costse of the latter kind are usually most 

 prominent. At great depths, and where the Madreporaria appear 

 to be very abundant, the specimens of Desmophyllum are usually 

 very granular externally, moreover they become attached to 

 compound forms of corals, and both have the same ornamentation, 

 so that it is difiicult not to believe in the Desmophyllum being 

 part and parcel of th^ growing mass. One specimen is attached 

 partly to broken specimens of dwarfed variety, with a small 

 calice, and without cost^. Other forms are finely pedunculate " 

 {loc. cit). 



I bring this character of variability prominently forward, so 

 that it may be seen what claims the present species has to be 

 regarded as distinct. 



Desmophyllum quinarium, n.s. 

 Corallum much depressed, narrowed very slightly at the base, 

 and twisted ; epitheca, coarse and irregular, with the costse 



