EEPORT ON THE KERATOSA. 41 



Colour. — Violet. 



HaUtat.—^taiioxi 188, September 10, 1874, lat. 9° 59' S., long. 139° 42' E. ; depth 

 28 fathoms ;, green mud. 



Family Spoxgelid^, F. E. Schulze, 1878. 



Dijsideidm, Gray, 1867, and Marsliall, 1881. 



Arenosa, Carter, 1875. 



Spmgiadce {e. p.), and Hireiniadce (e. p.), Hyatt, 1877. 



Keratosa with flagellated chambers of more or less regularly roundish outlines, 

 communicating by means of numerous pores in their walls with inhalent, by means of 

 one wide mouth Tsdth exhalent, cavities ; ground-mass transparent, without granules. 

 Axis of fibres thin ; fibres cored in most cases with foreifrn enclosures. 



Spongelia, Nardo. 



Dysidea, Johnston. 



Sponge! ia, Dysidea, and Psammasais, MarsliaU. 



Spongelidse with large flagellated chambers ; outer surface proYided with conuli. 



Spongelia spinifera, F. E. Schulze. 



Spongelia spinifera, F. E. Schulze, Zeitsckr. f. wiss. Zool, Bd. xxxii. p. 152, 1878. 



This species, established by F. E. Schulze in the year 1878 for some forms from the 

 Adriatic, is characterised by him as follows : — " The conuli, 5 to 8 mm. high, situated at 

 equal distances from one another, run out in simple thorn-like processes ; among the 

 simple ramified primary fibres no communicating secondary fibres are to be found, so that 

 accordingly the skeleton forms no network." The chief character, since the size of the 

 conuli is in other representatives of the genus variable, is thus the dendroid ramification of 

 the skeletal fibres which do not anastomose with one another. In this chief character both 

 the Challenger specimens, which I have determined as Spongelia spinifera, agree ; but 

 while one, diff"ering from the Adriatic forms as regards its lower conuli, agrees with them 

 in its mode of growth, being found like them in the form of a crust, the second specimen 

 difi'ers from them even in this latter point, presenting a laterally compressed leaf 25 mm. 

 high, 20 mm. broad, and 5 mm. thick in the middle, and rather thinner near the border. 

 The conuli of both the specimens do not exceed 4 mm. in height, and in accordance with 

 this peculiarity I propose to establish for them an independent variety — p>arviconulata, 

 while the designation magniconulata might be used for forms like the Adriatic Spongelia 

 spinifera. No peculiarities of consequence were noticed with regard to the structure of 



(zool. CHALL. EXP. PAKT XXXI. — 1881.) Eh 6 



