112 MADEEPOEAEIA. 



tubular, 4 mm. long. Corallum very porous ; surface reticulate, finely echinulate ; wall 

 fragile, striato-reticulate. 



Pacific Ocean : Great-Barrier Reef area. 



a. Port Denison. [Saville-Kent Coll. 96. 6. 8. 274. (Type.) 



107. Madrepora latistella. (Plate IX. fig. B.) 

 Madrepora latisUUa, Brook, Ann. Mag. N. H. 1892, vol. x. p. 459. 



Corallum subhorizontal, without fusions. Branches 9 to 10 mm. diameter. Branchlets 

 on the upper surface erect, spiciform, simple or in groups of 2 to 3 from a common base, 

 rarely proliferous except near the margin of the colony; length 2"5 to 3 cm., diameter 5 mm. 

 Axial corallites cylindrical, 2*5 to 3 mm. diameter, 2 mm. exsert. Radial corallites chiefly 

 gutter-shaped or labellate, usually ascending ; wall of moderate length, but becoming reduced 

 to a crescentic rim near the base of the branchlets ; length 1"5 to 2 mm., diameter 1'3 mm. ; 

 on the marginal branches the corallites are stouter, further apart, and many which are tubular 

 or subtubular indicate new proliferations, those which are 4 or 5 mm. long already bear 

 several small buds. Star well-developed ; even in corallites situated near the apex of a 

 branchlet the primary septa are very prominent and a second cycle exists in rudiment ; lower 

 down the second cycle is also well-developed. Immersed corallites are numerous on the 

 upper surface, and extend to the basal parts of the branchlets. On the under surface the 

 branchlets extend obliquely, and often bear several elongate tubular corallites 6 mm. or more 

 long and 2 mm. diameter. Corallum moderately porous ; surface strongly striato-echinulate ; 

 wall strongly striate, echinulate at the base. 



The species bears a close general resemblance to M. patula, but differs in the form of the 

 corallites, in the importance of the septa, in the condition of the surface, as well as in 

 minor points. 



Pacific Ocean : Great-Barrier Reef area. 



a. Port Denison. Saville-Kent Coll. 92. 6. 8. 275. l 



b. Thursday Island. Saville-Kent Coll. 92. 6. 8. 316. /'^yP^^- 



The following species are also provisionally referred to this subgenus. The first 

 shows an aflBnity to the subgenus Conocyathus, the others are apparently related to 

 Lepidocyathus : — 



108. Madrepora polystoma, (Plate XIX. fig. A.) 



Madrepora polystoma. Brook, Ann. Mag. N. H. 1891, vol. viii. p. 466. 



Corallum corymbose and complanate below, 35 cm. wide and 12 cm. high, closely 

 resembling that of M. concinna in habit. Branches complanate' below, the basal parts fused 

 into a solid plate with immersed corallites ; distal parts with hemicotyloid corallites on the 

 under surface and a few lateral, tubular or conical ones. Branches on the upper surface 

 about 4 cm. long and 1*3 to 1*5 cm. thick, angular below, with crowded immersed corallites ; 



