MADREPORARIA WHITELEGGE. 365 



band of low rounded tubercles, 3 to 4 mm. diameter, 2 to 4 mm. 

 high, and about 5 mm. apart at the apex. 



The calicles are either level with the surface or slightly de- 

 pressed ; they are 0'5 in diameter, and vary greatly in distance 

 apart. 



The ccenenchyma is comparatively smooth and marked with a 

 vermicular reticulation 



The echinulse on the upper surface are slightly compressed at 

 the base, above they are somewhat irregular and bear numerous 

 acute spinules; they are from 1 to 2' 5 mm. in height and about 

 0-5 mm. apart. 



MONTIPORA SCABRICULA, Dana. 



Montipora scabricula, Dana, Zoophytes, U.S. Explor. Exped., p. 

 502, pi. xlvi., fig. 2. 



One small specimen which may be referred to this species ; the 

 fragmant is, however, too much worn for correct determination. 



Lagoon shore. 



MONTIPORA BXSERTA, Quekh. 



Montipora exserta, Quelch, Ghall. Rep. Zool., xvi., p. 174, pi. 

 viii., fig. 5 - 56. 



There are two specimens of this well marked species ; one is 

 small, flat, incrusting, and measures 5 cm. in length, 3 - 5 cm. in 

 width, and 9 mm. in thickness at the broken edge; the other is 

 cushion-shaped, 13 cm. long, -7 cm. broad, and 2 cm. thick, with 

 a very even surface studded with numerous wart-like elevations; 

 The surface is perforated here and there by a boring mollusc, 

 which may be the cause of the warty growths. The calicles are 

 between % 65 and 0'75 in diameter and about the same distance 

 or more apart. The apertures on the level parts of the corallum 

 are surrounded by a very shallow rim, and all the septa are more 

 or less exserted. The directives are broad and have their inner 

 apices higher than the outer. The septa are usually in two cycles. 

 A few large calicles are present in which a third cycle is more or 

 less complete. 



The surface of the ccenenchyma is reticulate, porous, and 

 minutely echinulate. The echinulse vary considerably ; on the 

 higher parts they chiefly consist of spiniform granules. On 

 rapidly growing parts and at the margin they are elongated and 

 more closely packed ; their distance apart at the apex is usually 

 about 0'2 mm. 



