Mr. S. 0. RiJlej oa Sponges. 185 



Axinellidae. 



Ech inodicttj itm taesenterinum . 



Spangia mesenterina, Lamarck, Ana. Mus. Hist. Nat. xx. p. 444. 

 ^chinonema vasiplicata, Carter, Auu. & Mag, Nat. Hist. 1882, ix. 

 p. 114. 



This fine species has been described under the above two 

 haines. I have ah-eady stated (Report on the Zoological 

 Collections made during the Voyage of H. M.S. 'Alert:' 

 London, 1884, p. 454) that Mr. Carter's species is referable 

 to Echinodictijum^ mihi. Examination of a specimen in the 

 Museum at the Jardin des Plantes, Paris, which agrees with 

 Lamarck's description, has shown me that that species is iden- 

 tical with the former. 



Suberitidae. 



For the view that the Suberitidse are really Monactinellid 

 and Monaxonid, derived from a Diactinellid type, and not 

 reduced Tetractinellids, evidence is afforded by the heads of 

 the spicules of the species described below. In those heads 

 which {as in many other species) exhibit a small terminal 

 rounded process or knob, the central canal shows a small in- 

 flation near the centre of the larger division of the head, and 

 a fine undilated prolongation in the direction of (but scarcely 

 extending into) the small process, apparently indicating that 

 the spicule was originally prolonged on both sides of the present 

 head, the small terminal knob of the head and the fine prolon- 

 gation of the central canal being rudiments of the second ray. 

 An additional argument in favour of this view is the fact that 

 the projection and its corresponding section of central canal 

 occur in young spicules, and tend to be lost in adult examples. 



Suherites niassa, Schmidt, var. 



As the original form of this species has (like, indeed, most 

 known species of Suheriles) never been fully characterized, I 

 think it well to describe some interesting specimens from 

 Mauritius, which differ from the originals only in their external 

 form. 



Sponge massive, consisting of vertical convolutions or 

 sinuous laminae, about 45 millim. (If inches) high, and 10 

 millim. thick above, appressed towards each other, dividing 

 and uniting with each other ; they are rounded above and 

 rise to approximately the same height. General appearance 

 that of the human cerebrum. Vents scattered, subcircular, 

 about 1 millim. in diameter, placed low down on the sides of 

 the convolutions at some distance below the top of the sponge; 



Ann. & Mag. N. Hi^t. Ser. 5. Vol. xiv. 15 



