BENDY NON-CALCAREOUS SPONGES 123 



Register Numbers, Localities, &c. XX. 2, 8, Adatra ; XXII. 1,3,^ mile N. 

 of Poshetra, 20.12.05; XXIV. 1, 2, Kiu, low water, 24.12.05 ; XXVI. 3, 12, 

 Adatra Reef, 25 Dec. '05 \\ XXXII. 1, 2, 7, off Beyt ; XXXIV. 3 a, channel, 

 W. side of S. end of Beyt Island, 3-4 fms., 3.1.06. 



34. Desmacidon minor n. sp. (Plate III., Figs. 20a, 206.) 



There are two specimens of this sponge in the collection, both from the same 

 locality. One of them (R.N. XX. 6 a, Fig. 20a) is compressed, flabellate, with a much 

 contracted base, almost forming a short peduncle. The upper margin of the sponge 

 is widely extended and produced into short conical processes, apparently the ends of 

 laterally fused branches. The vents are of fair size, shallow and scattered on one surface 

 of the sponge only, not marginal ; owing to the maceration of the specimen they are no 

 longer very distinct. The surface is finely granular. The specimen measures about 

 26 mm. in greatest height, 41 mm. in width, and 3 mm. in average thickness. The 

 texture is soft and resilient ; the colour in spirit (after formalin), light brown. 



The second specimen (R.N. XX. 6 b, Fig. 206) is very similar in most respects, but 

 is divided into digitiform branches from the contracted base upwards, most of the 

 branches lying in approximately the same plane. The branches are subcylindrical or 

 slightly compressed, and about 3-6 mm. in diameter. The shallow vents tend to arrange 

 themselves in longitudinal series on the branches. The maximum height of the specimen 

 is about 33 mm. 



The skeleton is a sub-isodictyal reticulation of short oxea, but with the meshes 

 composed of plurispicular fibres in which the spicules are held together by a considerable 

 amount of very pale-coloured spongin. 



The spiculation consists of the following : 



(1) Fairly stout, slightly curved oxea, gradually and sharply pointed at each end, 

 measuring about 0-13 by 0-008 mm. Much more slender oxea also occur, which are 

 probably young forms. 



(2) Slender, palmate isochelae(" naviculiform ''), about 0-01 64 mm. long ; abundant. 

 This species might almost be regarded as a dwarf variety of Desmacidon compressa 



(Carter's Chalina compressa), which appears to be a South African species, but the 

 spicules of the latter are very much larger, the oxea measuring, according to Carter 

 [1882 bis], about 0-37 by 0-023 mm, and the isochelse (" naviculiform equianchorates ") 

 0-025 mm. in length. 



Register Numbers, Locality, &c. XX. 6 a, b, Adatra. 



35. lotrochota baculifera Ridley. 



lotrochota baculifera Ridley [1884]. 



lotrochota baculifera var. flabellata Dendy [1887]. 



lotrochota baculifera Topsent [1893]. 



