Sponge-fauna of Norway . 247 



ceeds, without altering the essential characters of Lamarck's 

 genus, to give it a new name. No wonder that complaints of 

 an overburdened nomenclature are becoming chronic ! 



In the years 1872-74 numerous descriptions of new species 

 belonging to the genera Cydonium, Geodia, and Pachyma- 

 tisma, accompanied by beautiful drawings, were published by 

 Bowerbank *. 



In 1874 likewise appeared the 3rd vol. of Bowerbank's 

 1 British Sponges,' containing a fine figure of that typical 

 specimen of Geodia zetlandica which had previously been ex- 

 amined and described by Fleming and Johnston. 



In 1873 Grube f described and figured a specimen of 

 Pachymatisma Johnstoni, Bwk., under the name of Caminus 

 osculosus. It came from the coast of St. Malo. 



In 1876:}: Carter described, with many interesting observa- 

 tions, two new species of Geodia — one with cribriform depres- 

 sions (G. nodastrella), and the other with a single vent 

 (G. megastrella) . 



The table given at the commencement of this paper repre- 

 sents the classification as it at present stands. The genera 

 appear to me to require fresh examination and revision ; but 

 this is a subject to which I hope on a future occasion to recur. 



Geodia Barretti, Bwk. § 



The specimen under description differs only in trifling de- 

 tails from Geodia Barretti, and must necessarily be included 

 in that species. 



In form it is almost spherical, 1 inch in diameter, free, with 

 a small Halichondroid sponge attached to it, the surface of 

 attachment measuring £ inch square. It possesses a single 

 circular oscule (PI. X. fig. 3) j\ inch in diameter, situated in 

 the centre of a low dome-shaped elevation, 0'15 inch in dia- 

 meter, which rises from a shallow annular depression. The 

 surface is smooth except for the protrusion of a few long fusi- 

 form acerate spicules at one or two particular spots, and of a 

 large number of minute acerates generally, which render it 

 finely hispid. 



The spicules (see figures on PI. XL) do not differ in charac- 

 ter from those already described by Bowerbank ; but it may 

 be as well to call attention to the great length of the shafts of 



* Proc. Zool. Soc. ] 872-74. 



t Mittheil. u. St. Malo u. Roscoff&c. p. 132, Tat'. 2. figs. S,lia-c. 



X Ann. & Mag. Nat. Hist. ser. 4, vol. .wiii. p. 397, pi. xvi. figs. 45-47. 



§ Phil. Tians. 1862, pi. xxxii. fig. 2 ; Hiet. Put. Sponges, i. 18(54, p. 107, 

 pi. xxviii. fig. 254 ; and Proc. Zool. Sec. 1872, p. 1U8, pi. xi. 



17* 



