L30 A. K Verrill — Berrmidian and West Indian Reef Corals. 



Mussa lacera (Pallas) Oken. 



Madrepora lacera Pallas, Elench. Zooph., p. 208, 1766. Esper, Pflanz., i, p. 148, 



pi. xxv, fig. 2, 1791. 

 Madrepora carduus Ellis and Sol., Zooph., p. 153, pi. xxv, 1786. 

 Mussa lacera Oken, Lehr. Naturg., p. 75, 1815. 

 CaryophylUa carduus Lam., Hist. Anim. sans Vert., ii, p. 229, 1816; ed. 2, p. 



357. 

 CaryophylUa lacera (pars) Ehr. , Corall. E. Meeres, p. 92, 1834. Edw. and Haime, 



Ann. Sci. Nat., ii, p. 238, 1849. 

 Mussa carduus Dana, Zooph. Expl. Exp., p. 175, 1846. Edw. and Haime, Hist. 



Corall., ii, p. 334, 1857. 

 LithophyUia lacera Edw. and Haime, Hist. Corall., ii, p. 291, 1857 (Young) + L. 



Cubensis, op. cit., p. 292. 

 Scolymia lacera Haime, Mem. Soc. Geol. France, iv, p. 279, 1852. Bruggmann. 



Ann. and Mag. Nat. Hist., xx, p. 303, 1877. Vaughan, op. cit., pp. 6, 34, 



1901. 



This large species is common in the Bahamas and southward to 

 Cnracao. 



On the Florida reefs it seems to be rather rare. It has not been 

 found at the Bermudas. It forms dichotomons clumps, often more 

 than a foot high and broad. The calicles, when full grown, are 

 mostly isolated and nearly circular. They are from 40 to 65 mm in 

 diameter, and sometimes more, but mostly about 5jO mm . The calicles 

 vary in depth, some being shallow, others rather deep. The septa 

 are numerous and strongly toothed, but the teeth vary widely in 

 form ; usually the distal ones are much the larger. The larger septa 

 are usually pretty thick, but sometimes they are thin and fragile. 

 The exterior is covered with rows of strong, acute costal spines. 



I regard the simple forms with broad calicles and wide base, 

 referred by Edw. and Haime to LithophyUia lacera, as the young of 

 this species before fission takes place. The two forms occur in the 

 same localities. It is certain that all the species of Mussa and 

 Isophyllia have such a simple young stage, before they begin to 

 divide, in which the diameter of the cup equals or exceeds that of 

 the adult calicles after division. The size of the calicles and the 

 number and character of the septa and their denticulations all corre- 

 spond well in the two forms. Moreover, I have seen specimens of 

 the simple Lithopyllia-iovm in which infoldings of the margin had 

 already taken place, to begin the process of fission. 



If this form be not the young of " carduus,'''' as I believe, then its 

 young have not been discovered, which would be remarkable in the 

 case of such a large and common species. 



