116 OKHAMANDAL MARINE ZOOLOGY REPORT— PART II 



of the reticulation. , The dermal skeleton is an irregular, unispicular reticulation 

 of oxea, in which the individual spicules overlap one another extensively ; without 

 obvious spongin. 



The spicules are very slightiy curved oxea, gradually and sharply pointed at 

 each end, measuring about 0-13 by 0-006 mm. 



This species shows very clearly the difficulty of differentiating between the 

 genera Pachychalina and Siphonochalina. The whole structure of the stolon is 

 typically that of a Pachychahna, and only the presence of the tubular ascending 

 branches justifies its inclusion in SiphonochaUna. The entire sponge resembles 

 Siphonochalina crassifihra on a smaller scale, but with decidedly larger spicules. 

 It makes a near approach to my Pachychalina subcylindrica from Ceylon [1905]. I 

 have already pointed out the resemblance which it bears to Reniera fibroreticulata 

 {vide supra and cf. Fig. 12). 



Register Numbers, Localities, c&c. XXVI. 4, Adatra Reef, 25 December, '05 ; 

 XXXIII. 5, Dhed Mora and adjacent rocky ground between Beyt and Aramra, 

 1 fm., 21.12.05. 



Chalininae spp. 



There are several other small chalinine sponges in the collection which are 

 not in a sufficiently good state of preservation or sufficiently well characterised to 

 make identification or description desirable. 



25. Desmacella tubulata Dendy [1905]. 



It is very interesting to meet with this curious and well characterised species 

 again in Mr. Hornell's collection. So far as I am aware it has not been recorded 

 since I first described it from Ceylon in 1905. The material now before me 

 consists of a number of fragments of thin-walled tubes, some of which seem to 

 have been 10 mm. or more in diameter. At one point some of these tubes have 

 grown into close union with a specimen of Gellius sp. 



The agreement in spiculation with the type is very close, but I must add 

 that I have observed a few slender toxa, about 0-032 mm. long, on one occasion 

 arranged in a sheaf or toxodragma, differing only in the curvature of the toxa 

 from the smaller trichodragmata. I did not observe any toxa in the type speci- 

 mens, but probably they occur there amongst the vast number of trichodragmata. 

 I must also add to my original description that the individual trichites of which 

 the trichodragmata are composed, although slender,, are not nearly so slender as 

 in some cases. The sheaves or dragmata themselves may be very thick. 



Previously Jcnown Distribution. Gulf of Mannar (Dendy). 



Register Number, Locality, c&c. XXVI. 7, Adatra Reef, 25 December, '05. 



