25 



XXXI. Spirastrella bonneti. 



1906 (0) Topsent pp. 570, 571, 573—575- 



Topsent describes a "new species" under the name Spirastrella bonneti. It is a great 

 misfortune that we have here again to do with a "new species" the description of which is 

 not accompanied by figures. As far as can be judged from this description the shape is cushion- 

 like, provided with numerous "conules" of 5 — 10 mm. These cones are "rattachés les uns aux 

 autres par des brides membraneuses minces". This feature reminds us of S. insignis and of 

 some specimens of S. pa nis of Thielk. In this connection it is worth while to draw attention 

 to the fact that Topsent says about the megasclera : "lis rappellent 1111 peu les styles de 

 Spirastrella insignis Thiele, mais ils mesurent seulement o millim. 3 a o millim. t,t, de longueur 

 And about the microsclera the author writes : "Il existe aussi une certaine similitude entre ces 

 spicules et les microsclères correspondants de Spirastrella insignis, mais des spirasters de 

 5". Bonneti 1'épaisseur ne dépasse pas o millim. 0045, ni la longueur o millim. 023". As often 

 stated before and as I will more fully explain hereafter, it is impossible to make specific 

 distinctions in Spirastrella on account of the size of the spicules. And since I unite i'. insignis, 

 panis, a. o. with wilsoni, purpureum, areolata a. o. on one side and with ennetatrix on the 

 other side, it consequently follows that I believe 5. bonneti to be nothing but a specimen of 

 A. purpureum of Lamarck. 



XXXII. Spirastrella digitata. 



1909 Hentschel p. 385 — 386; PI. XXII, fig. 7 and woodcut. 



"Ein massiger Schwamm mit Fortsatzen von fingerförmiger, keulenförmiger, lappiger 



oder knolliger Gestalt Die Oberflache ist etwas rauh, die Farbe im trockenen Zustande 



hell-orange-braun, innen fast weiss". Comparing this description and the illustration with specimens 

 of the Siboga-material I find it marvellously in accordance with S. K. 2049. In spiculation the 

 sponge cliffers in so far as the styli or tylostyli are stouter in my specimen, whereas the spini- 

 spirae are much more slender. In this respect the sponge approaches Suberites wilsoni (B. M. 22) 

 and others. There seems to me no doubt as to the identity of Hentschel's 5. digitata with 

 my trop. tubulifera ; it forms a transition between this tropus and trop. pyramidalis — once 

 more a proof of the impossibility at present to distinguish species. 



u-> 



To resumé the conclusions we arrive at by the above considerations, we find that a 

 quantity of specimens belonging to the genus Spirastrella may be identified with "species" 

 previously described, and that some of these "species" are mere synonyms. Thus we have 

 already established the following points. 



i° Identical with Spirastrella etenctatrix are: g2a-l, 426 d, S. papil 'losa, S. pa nis and S. insignis. 

 2° Identical with Spirastrella dceuinbens are: 5. Instel 'lata, S. transitoria, S. sanilunaris, 1031, 

 1455 a-c, 1945, 1402 and 1421. 



S1BOGA-EXPEDITIE Vla'. 4 



