94 MADREPORARIA. 



This unique specimen, distinguished from all others in the Collection by the delicacy and 

 regularity of its surface ornamentation, is fractured across, and reveals a section, 11 cm. thick. 

 From this section the arrangement and great lengthening of the calicles in the pulvinate type 

 of growth can be weU seen. The calicles develop tabulte about 1 mm. apart. The costal 

 element of the coenenchyma is more strongly developed than the synapticular, the echinulte 

 tajiering and bending upwards, as, in the course of growth, they get further and further from 

 the calicle on whose wall they originally appeared. 



The specimen is further remarkable for the presence of a great number of minute 

 tubicolous worms whose usually pink calcareous tubes grow upwards among the lengthening 

 calicles to open on the living face of the corallum. The coral seems to have become adapted 

 to its invader, for there is no sign of abnormal growth immediately round the worm tubes, 

 showing disturbance of the normal conditions, as there is in the case of Adrccopora kcnti 

 (p. 98). 



a. Solomon Islands. Dr. Guppy. (Type.) 



Species 9. Astrseopora hirsuta. (ri. XXXIII. fig. 13.) 



Description. — Corallum showing the pulvinate type of growtli, a well-developed 

 secondary epitheca on the under surface of the pendent edges. 



Calicles so slightly and regularly projecting that the surface appears even ; crowded, less 

 than their diameters apart, conspicuous, irregularly circular (ca. 2 • 5 mm.). Two cycles of 

 septa, the primaries meeting in the centre, deep down in the fossa (5-6 mm.) but not fusing. 

 At the pendent sides, the calicles are shallower and tlie septa well marked. In the light 

 reticular margins of the slightly protuberant calicles, the primitive connection between the 

 septa and the reticulum is quite obscured. On the summit of the growth, the interstices are 

 pitted with young calicles which first appear as irregular breaks in the reticulum. Tabula 

 develop in the lengthening calicles. 



The ccenenchyma differs from that of any other type. The synapticular floors along 

 the summit of the coral are either very slightly or very slowly developed, so that the costal 

 elements, the echiuulte, stand up in the valleys like long, slender, but irregular bristles, ending 

 in a single point or in two points, but not in a group of fine points. This character of the 

 cojnenchyma ceases near the pendent sides, where the synapticular floors are more developed, 

 and the echinulpe are short, irregular, and jagged. In section, while the vertical element is 

 very pronounced, the synapticular is but feebly developed, and does not form the regular tiers 

 of floors characteristic of the genus. 



There is, unfortunately, only a single fragment of this coral. It is, however, sufficient to 

 reveal the method of growth, and to show thecharacters, above described, which constitute it 

 a new type. 



a. Rocky Islands, Great Barrier Reef. Saville-Keut CoU. (Type.) 



