MADREPOEARIA WHITELBGGE. 351 



or to secondary spinular growths at the summits, but the average 

 distances, when numerous measurements are taken, prove to be 

 pretty constant and equally as reliable in corals as in other 

 organisms determined by micrometric measurements. 



The species described as new are Madrepora spinulifera and 

 M. impressa. The former is referable to the subgenus Odontocya- 

 thus and the latter to the subgenus Isopora. 



Order MADREPORARIA APOROSA. 



FAMILY TURBINOLID^. 



CARYOPHYLLIA CLAVUS, var. EPITHECATA, Duncan. 

 Caryophyllia clavus, var. epithecata, Duncan, Trans. Zool. Soc., 

 viii., p. 311, pi. xlviii., figs. 13-16. 



A small immature example in the collection is referable to this 

 variety. 



The corallum is erect, elongate, conico-turbinate, incrusting at 

 the base and elliptic in outline at the summit. 



The epitheca is finely granulate and extends from the base to 

 the calicular margin. 



The costse are slightly prominent above, and cease at the median 

 constriction below. 



The septa are strongly exserted, radiately granulose at the sides 

 and evenly rounded at the summits. 



The pali are sinuate and sparsely spinose. 

 The columella consists of two spirally twisted processes. 

 There are forty septa and ten pali. The latter are opposite the , 

 tertiaries. 



Height of corallum 14 mm. 



Diameter at apex 7 by 9 mm. 



,, base 7 mm. 



pedicel 3 mm. 



Obtained in from forty to seventy fathoms. 



FAMILY OCULINID^. 

 I r STYLOPHORA DIGITATA, Pallas. 



Stylophora digitata (Pallas), Klunzinger, Die Korall. Rothen. 

 Meeres, p. 61, pi. v., fig. 5 ; pi. viii., fig. 1. 



There are eight examples of this species, exhibiting considerable 

 variation. 



In the young the branches are subcylindrical, transversely 

 nodose, and somewhat conical at the extremities. The larger 



