THE ALCYOXABIA OF THE MALDIVES. 527 



The mesenteries and mesenterial filaments are more pronounced in this than in any other 

 species; (4) the siphonozooids are extremely degenerate and have no apertures to the ex- 

 terior. They are represented by vertical caeca from the traiasverse vessels of the superficial 

 canal system; (5) the transverse and internal canal systems are well-marked; (6) zoochlorellae 

 are fairly numerous. 



This species resembles Sc. capitale in certain respects: the tough fleshy texture of the 

 colony; the fairly large autozooids; and the presence of a double row of rudimentary pinnules 

 on the tentacles. It differs from that species, however, in that the mesenteries and mesenterial 

 filaments are more strongly marked, the siphonozooids are more degenerate, and the canal 

 system is not so clearly defined. 



13. Sclerophytum gardineri sp. nov. (PL XXXI. fig. 28). 



A single complete and well-preserved specimen was taken in shallow water from Hulule, 

 Male Atoll. 



The colony is 40 mm. high and is 48 x 26 mm. broad, irregularly cup-shaped and laterally 

 compressed (fig. 28). The stalk is 20 mm. high and is 39 x 20 mm. broad, its surface is 

 somewhat wrinkled and is hard, granular and unpelding to slight pressure. The capitulum 

 is irregularly cup-shaped with irregular long and slender lobes, arising from the middle and 

 edges of the cup. The cup is 40 x 31 mm. in diameter and in the middle is 20 mm. deep ; 

 there are two clefts in the sides of the cup. The lobes are brittle and are often branched. 

 The largest lobe {I.) arises slightly obliquely from the middle of the cup and is 28 mm. high 

 and 9 x 6o mm. in diameter near the base. It gives off numerous digitate branches which 

 vary in length from 2 to 7 mm., but having an almost uniform breadth of 3 mm. Owing 

 to the presence of numerous spicules the surface of the capitulum like that of the stalk 

 is hard and granular. In spirit the specimen is of a dark cream colour. 



Spicules. The hard and brittle nature of the coral is due to the presence of in- 

 numerable spicules. Clubs and slender spindles, similar to those of other species and measuring 

 ■1 — "2 mm. in length and '0.5 — 06 mm. in breadth, are crowded near the surface. The 

 tuberculate spicules are similar to those of other species, the majority are spindles about 

 3 mm. long and '8 — 1 mm. broad. A few are slightly forked as in Sc. densum and Sc. hirtum. 

 The outer walls of the anthocodiae are studded with minute spindles as in many other species. 



Autozooids only are present and the species may be regarded as having lost its 

 siphonozooids. The autozooids are very small, and as many of them are almost completely 

 retracted only a few can be distinguished on the surface of the capitulum (fig. 28). A fairly 

 expanded autozooid measures '4 — 'o mm. across the crown. The tentacles are very minute, 

 and when extended average only "3 mm. in length. The pinnules are represented by very 

 slight iadentations of the lateral walls and are not easy to distinguish. The stomodaeum 

 is fairly long, with much convoluted walls; its siphonogh^h is large and is provided with 

 long cilia. 



Mesenteries. The dorsal mesenteries are clearly marked and are very long; they are 

 pro\-ided with long, broad grooved and ciliated mesenterial filaments, which are much con- 

 voluted at the beginning of their course. Ventral and lateral mesenteries are present but 

 below the stomodaeum diminish rapidly in size, and consequently have a very short free 

 edge with no filaments. Ova in all stages of development are present, and are frequently 

 to be found on the dorsal mesenteries. In this respect this species is interesting, for ova 



