354 Mr. R. Kirkpatvick on 



microscleres are strongylote or substylote, slightly curved, 

 finely and irregularly spined, and 90-144 /j. in length by 

 3-5 fi in breadth. 



After a careful examination of Hancock's specimen I 

 consider Dyscliona purpurea to be a genuine boring-sponge. 



To return to the Funafuti species : the Echinopora has 

 been bored by Cliona Schmidti and by the filamentous alga 

 Achlya, and precautions were necessary to ensure that the 

 Dyscliona was obtained free from admixture with the Cliona. 

 Fragments of the coral with the cavities lined solely with the 

 yellow tissues of Dyscliona were separated, none of the tylote 

 and spinispirular spicules of C. Schmidti being found. Hence 

 I consider that these excavations were formed by the 

 Dyscliona. Further, the existence of two closely allied 

 species, D. purpurea and D. Davidi, ramifying deep down in 

 the substance of shell and coral, tends to confirm the hypo- 

 thesis that we have here genuine boring-sponges. 



If this supposition be correct, the true position of these 

 species would seem to be in the Clavulid family Clionidas, 

 despite the fact that only diactinal megascleres are present in 

 them and that true spinispirulas do not occur. The un- 

 doubted Clionid sponges, Cliona nodosa and C. labyrinthica, 

 have only diactinal megascleres; and, further, the spirally- 

 spined microscleres of Dyscliona Davidi may be regarded as 

 modified spinispirulas, the modification having proceeded still 

 further in D. purpurea. 



If D. Davidi and D. purpurea are not Clionids we have to 

 assume that the faculty of boring belongs to Haliehondrine 

 as well as to certain Clavulid and Tetractinellid sponges. 



To have placed these two species in the genus Cliona 

 would have been to unduly disturb what Topsent has termed 

 the " incomparable homogene'ite " of that genus; accordingly 

 they have been put into a new genus, Dyscliona. The new 

 species is named after Prof. Edgeworth David, the leader of 

 the Australian Boring Expedition. 



Locality. Funamara and Funafuti Islet, 25-45 fath. 



Latrunculia clavigera, sp. n. (PI. XIV. fig. 2, a-e.) 



Sponge forming a very thin greyish-white crust (on the 

 stem of a Goryonia). 



Skeleton formed of a surface-layer of discasters, and, beneath 

 this, of scattered tylotes arranged horizontally ; scattered small 

 nail-shaped tylotes with points upwards and heads on basal 

 surface. 



Spicules. — Megascleres : tylotes, average size 850 x 9 /j,, 



