MADEEPORA. 31 



another. Diameter of main branches 2*8 to 3*3 cm., length about 35 cm. Penultimate 

 divisions nearly 2 cm. diameter, about 4 cm. long, and with a crown of buds at the apex. 

 Axial corallites nearly 4 mm. diameter and 4 mm. exsert; sometimes 4*5 mm. diameter, with 

 only 1 mm. aperture and a very thick porous wall. Radial corallites large, appressed, lialf 

 tubular, up to 6 mm. long and 3 mm. broad, but a little irregular both in size and disposition. 

 There are no truly immersed corallites, except in the lines of fusion. Directive septa long, 

 the others shorter, with or without a rudimentary second series. Corallum stony, but a 

 little porous ; surface spongy-echinulate ; wall strongly ribbed, becoming echinulate below. 



The above description is based on a specimen in the Paris Museum, from the Galapagos 

 Islands. Another specimen, also forming part of the collection of M.-Edwards, but without 

 habitat, differs in having smaller radial corallites, 3 mm. long and 2 mm. diameter ; the 

 apex of this specimen is not preserved, so that one cannot decide if the axial corallites were 

 of the same size as in the type. 



Galapagos Islands. i 



4. Madrepora intermedia. (PI. I. fig. C.) 



Madrepora intermedia, Brook, Ann. Mag. Nat. Hist. 1891, vol. viii. p. 463. 



Corallum arborescent, similar to that of M. secunda in habit. Main branches 2 to 2*5 cm. 

 thick and 25 em. long, moderately subdivided, especially near the apex. Ultimate divisions 

 3 to 6 cm. long and 1 cm. or more thick, gradually tapering to a blunt apex, or more rapidly 

 tapering and pointed. Axial corallites 2-5 mm. diameter, 0-5 to 2 mm. exsert, but usually short ; 

 aperture large, frequently oval ; primary septa well developed, second series not prominent. 

 Radial corallites tubular, spreading, very variable in length and also in diameter. The 

 majority extend almost at right angles to the branch, excepting near the apex, and have a 

 more or less oblique aperture ; they are about 3 mm. long and 2 mm. diameter ; wall firm, 

 but not thickened. Numerous short tubular to subimmersed corallites occur between the 

 others, varying from 1 to 1-5 mm. in diameter. The corallites become short and thickened 

 wart-like on the main branches, whilst on the under surface the majority are immersed. 

 Primary septa narrow, but the directives are moderately prominent, and in the older parts of 

 the corallum may be broad. Corallum very porous, surface reticulate and echinulate; wall 

 striato-echinulate, becoming later echinulate in linear series. One specimen resembles 

 M. muricata f. palmata in habit, and consists of a thick solid frond with incipient branches 

 on the upper surface and numerous short ones at the periphery. 



This species differs from M. secunda in the form and markedly unequal size of the 

 corallites. From M. muricata f. cervicornis it differs in the form and angle of the corallites, 

 the density of the corallum, and also in the presence of numerous immersed corallites, 

 particularly on the under surface of the larger branches. 



Indian Ocean : Maldive Islands. 

 a, h. Maldive Islands. Purchased. 86. 11. 22. 6 & 10. (Types.) 



c. Maldive Islands. Purchased. 86. 11. 22. 11. (Var.) 



f2 



