130 OKHAMANDAL MARINE ZOOLOGY REPORT— PART II 



end ; size about 0-14 by 0-0041 mm. (2) Spined styli (acanthostyli) (Figs. 76, 76') ; 

 tapering gradually from the base to the sharply pointed apex ; straight ; rather sparsely 

 covered with small spines, except towards the apex ; size variable, say about 0-11 by 

 0-01 mm. ; a number of very slender forms also occur (Fig. 76'). 



The sponge also contains numerous other types of spicule, most of which, at any 

 rate, have certainly been derived from other sponges, including Spirastrella, Esperella, 

 Donatia and Eeniera. There are, however, a fair number of stoutish, strongly angulated 

 toxa, a very few minute Clathria-hke, palmate isochelse, and a fair number of long, 

 straight, slender tylostyles with well-developed heads, which may possibly belong to 

 the species. 



The plumose character of the main skeleton fibres suggests a close affinity with 

 the genus Plumohalichondria. 



Register Number, Locality, dc. XXI. 1, 3, 4-7 fms. off Eupan Bandar and 

 Kutchegudh, 8.12.05. 



43. Raspailia fruticosa var. tenuiramosa Dendy. 



Raspailia fruticosa Dendy [1887]. 

 Raspailia fruticosa var. tenuiramosa Dendy [1905].' 

 Raspailia fruticosa var. aruensis Hentschel [1912]. 

 The two specimens in the collection differ from the Ceylonese types of the variety 

 in their much more sparingly branched character, being, in fact, less instead of more 

 bushy than the type of the species. . Both specimens, however, have much more 

 slender branches than the type of the species. As regards skeleton arrangement and 

 spiculation they agree very closely with the types of the variety. 



Previously known Distribution of the Species. Gulf of Mannar (Dendy) ; Aru 

 Islands, Arafura Sea (var. aruensis Hentschel). 



Register Numbers, Localities, <&c. II. 13, off Poshetra, January 7, 1906 ; XXIX. 2, 

 N. of Poshetra, 3|-4 fms., 20.12.05. 



44. Acarnus tortiliS Topsent[1892 6is, 1897, 1904]. 



I identify with this widely distributed but apparently rare species a small, pre- 

 sumably encrusting sponge of a brown colour and irregular shape. The spiculation 

 agrees closely with that described and figured by Topsent for his species, even down 

 to the minute spination of the bases of the stout styli and the ends of the diactinal mega- 

 scleres. The very characteristic grapnel-spicules, with usually four strongly recurved, 

 sharp hooks at the apex, strongly spined shaft, and base with spines curved in the 

 opposite direction, are identical. The toxa, however, appear to be all of the strongly 

 arcuate form, though varying much in dimensions. The chief difference that I have 

 been able to detect, however, lies in the presence of a considerable amount of spongin, 

 partially uniting and enveloping some of the spicules, but this difference can hardly 



