174 CEYLON PEAEL OYSTER REPORT. 



cylindrus) hisptda, is readily distinguished by the details of its spiculation. I have 

 much pleasure in naming it after Mr. HORNELL, to whose energy this collection owes, 

 I am told, so much of its value. 



K.N. 59 (Stat. IV., off Karkopani, Gulf of Manaar). 



Agelas, DUCHASSAING and MICHELOTTI. 



Ectyoniuee in which the skeleton is composed of horny fibre echinated by verticillately 

 spined styli ; with no other spicules. 



For synonymy and references I must refer to the Report on the "Challenger" 

 Monaxonida (p. 163). 



Agelas mauritiana (CARTER). 



1883, Ectyon mauritianus, CARTER (54); 1887, Agelas mauritianus, RIDT.EY and DENDY (1); 

 1903, Agelas cavernosa, THIELE (87). 



This species is represented by a tubular fragment 31 millims. long and up to about 

 16 millims. in diameter ; widely open at both ends and with the wall of the tube only 

 about 3'5 millims. thick. It is of rather dark brown colour and firm, resilient 

 consistence. 



The skeleton is a close, irregular network of stout, amber-coloured horny fibre 

 echinated very abundantly by the characteristic verticillately spined styli, which 

 measure about 0'176 millim. by 0'016 millim. (including spines). 



This beautiful species has hitherto been recorded from Mauritius (CARTER), off 

 Tristan da Cunha (?) (" Challenger "), and from Ternate (THIELE). 



R.N. 358 (Ceylon seas). 



Agelas ceylonica, n. sp. Plate XII., fig. 9. 



The type specimen* consists of a few slender, anastomosing, sub-cylindrical branches, 

 arising from an irregular, proliferous basal crust attached to a calcareous nodule. The 

 branches are only about 2 millims. in diameter, and their surface is irregular and 

 sometimes minutely hispid. Texture (in spirit) compressible, resilient, fibrous and 

 fairly tough. Colour brown. Vents minute and scattered on the branches. 



The skeleton is an irregular network of pale-coloured horny fibre about 0'03 millim. 

 in diameter, abundantly echinated by the spined styli, which are occasionally also 

 found embedded lengthwise in the fibre, two or three side by side. 



Spicules. Verticillately spined styli (Plate XII., fig. 9), straight or slightly curved ; 

 the spines mostly small and conical, especially about the middle of the spicule ; those 

 at the base irregularly arranged, larger, and often hook-shaped, with the sharp points 

 curved towards the apex of the spicule ; apex sharp-pointed and free from spines for 

 a short distance. Size variable, but characteristically long, say about 0'24 millim. by 



* A second specimen closely resembles the type. 



