DENDY NON-CALCAREOUS SPONGES 107 



13. Gellius fibulatus (Schmidt) var. microsigma nov. 



Reniera fibulata Schmidt [1862]. 

 Reniera fibulifera Carter [1880]. 

 Gellius fibulatus Topsent [1892]. 

 Gellius fibulatus Dendy [1905]. 

 Gellius ridleyi (pars) Hentschel [1912]. 



Very little is known about the external form of the European type. Schmidt, 

 however, says that it is not easily distinguishable from small specimens of Reniera alba. 

 The latter is described (loc. cit.) as a shapeless crust between the branches of Clathria 

 and in other situations, with single vents on the summit of short, projecting tubes. This 

 description applies very well to a small specimen in Mr. Hornell's collection. It consists 

 of a thin crust growing over a mass of calcareous debris and giving off three short processes 

 of unequal length, the longest measuring about 10 by 3-5 mm. The processes are 

 hollow, and each bears a terminal vent. 



The specimen seems to differ from the European form only in the small size of 

 the sigmata. The oxea measure about 0-25 by 0-01 mm., which seems to agree very 

 well with the type, but the sigmata measure only about 0-0164 mm. from bend to 

 bend. 



Previously known Distribution of Species. Adriatic (Schmidt) ; North Atlantic 

 (Topsent) ; Gulf of Mannar, Ceylon Seas (Carter, Dendy) : ? other localities in Indian 

 Ocean (see under Gellius ridleyi). 



Register Number, Locality, &c. XXIII. 7, off Dwarka, 15-17 fms., 12.12.05. 



14. Gellius ridleyi Hentschel. 



(For possible Synonymy, see Hentschel [1912]). 



I refer to this species a number of irregularly massive specimens bearing large vents 

 at the ends of deep, cylindrical oscular tubes. The largest specimen (R.N. XVII. 1) 

 is a clathrous mass of thick, anastomosing branches, for the most part vertical and more 

 or less fused laterally ; each pierced by a wide, cylindrical oscular tube. Colour in spirit 

 (after formalin), light brown. Texture loose and friable, slightly fibrous. The whole 

 mass measures about 70 mm. in greatest breadth and 65 mm. in height, but it has been 

 a good deal damaged. The oscular tubes measure up to 10 mm. in diameter. 



The skeleton is a sub-isodictyal reticulation of oxea, with only a slight tendency 

 to collect in fibres. The oxea are gently curved, gradually and sharply pointed at each 

 end, and measure about 0-2 by 0-0096 mm. ; numerous more slender forms occur, 

 presumably young. The sigmata are simply C-shaped, or only slightly contort, slender, 

 and measure about 0-02 mm. from bend to bend. 



Hentschel distinguishes his species from the European Gellius fibulatus (Schmidt) 

 by the spicular measurements. He states that in the Atlantic-Mediterranean form the 

 oxea measure more than 0-22 mm. and the sigmata more than 0-028 mm. in length, 



