MADREPORARIA. 789 



thickened, calices narrower and hence appearing deeper, septal teeth not so markedly in- 

 creasing in size towards the axial fossa, sometimes meeting over, sometimes merging into the 

 smaller and less distinct columella. 



Locality. Minikoi and Hulule, E. and W. reefs. 



66. Prionastraea suvadivae, n. .sp. 



A rounded head, 9 cm. across x 6 cm. high, stalk covered by organisms, the greater part 

 dead but calices quite distinct and 18 still alive when obtained. 



Corallites varying up to 28 mm. long but the actual cavities much less, the calices not, 

 indeed, averaging more than 1.5 mm. broad, 8 — 10 mm. deep. Dividing walls appearing from 

 the surface a little hollowed out and exceedingly thick, 2 — 10 mm., but the greater thickness 

 is made up of endothecal vesicles and very oblique dissepiments, reaching to within '5 mm. 

 of the granulated tops of the septa which are continuous between the calices. Septa numbering 

 30 — 40, smooth sided, set with 8 — 12 blunt, low, subequal teeth which on about 18 of the 

 larger, merge into the trabeculae of the rather small, coarse columella. Endothecal dissepiments 

 about 1 mm. apart, exceedingly oblique. Only one bvd showing and that from about half 

 way down the septa. 



It is obvious that the circumstances controlling the growth of this specimen were 

 eminently unfavourable — it was probably growing on the edge of a lagoon shoal and fell off 

 into deeper water, the muddy bottom of which was slowly killing it — its very thick walls 

 being a character associated generally with the edges or less vigorously growing parts of 

 colonies. Yet it exhibits this last character to a degree more extreme than described in 

 any other species. Its nearest ally is, in my opinion, P. favosa, but it is a distinct species. 

 I give it a geographical name, as I am uncertain as to which of its characters are really 

 of specific importance, although certain suggest other and more appropriate names. 



Iiocality. Suvadiva, 25/. 



Genus Merulina. 



67. Merulina ampliata Ell. and Sol. (PI. LXIV. figs. 47, 48.) 



Ell. and Sol, Zooph. p. 1.57, PI. XLI. figs. 1 and 2; Esper, Pflanz. t. I. p. 96, PI. LXXVII. ; 

 Dana, p. 272, xv. 2; Ed. and H., ii. p. 628. 



A single large specimen and several small pieces, all from the W. Reef of Hulule, which 

 agree in every respect with the above descriptions. Off the outer slope at Goidu this or a 

 similar species is very abundant forming foliaceous colonies two or three yards across and high. 



68. Merulina prolifera Quelch. 



Quelch, Cludlenger Report an Reef Corals, p. 110, PI. II. fig. 1. 



Three small specimens fi-om Suvadiva 35/, 8. Nilandu 36/, and N. Male 24/, appear 

 to belong to this species, the type of which I have examined. 



101—2 



