133 



PORIFERA. II. 



Ser. 2, V, bis, suppl. 118), on tlie other hand, at all events only the former is incrustans; the tornote 

 figured by Topsent has smooth ends, but perhaps the spines, which may be very fine, have been over- 

 looked; the tornote with cleft ends figured for var. viscosa, on the contrary, belongs, no doubt, to the 

 following species. Finally Topsent (Resultats du Voyage du S. Y. Belgica, 17) describes a Deiidoryx 

 incrustans var. australis; on account of the sizes of the megascleres, the styli are 0-5 — o - 6 mm , and the 

 tornotes o'32 mm , I think it more probable that it is an independent species. - - The Halichondria incru- 

 stans var. with angulated anchorate and smooth acuate from the west coast of Florida mentioned 

 by Carter (Proceed, of the Acad, of nat. Sc. of Philadelphia 1884, 205) cannot be the present species, 

 but must belong somewhere else. 



2. M. rosacea Lieberk. 

 PI. IV, Fig. 8. PI. XIV, Fig. 4 a— h. 



1859. Halichondria rosacea Lieberkiihn, Arch, fur Anat. 521, Tab. XI, Fig. 2. 



1862. Myxilla rosacea O. Schmidt, Spong. des adriat. Meer. 71. 



1864. Myxilla tridens O. Schmidt, ibid., Suppl. I, 36, Tab. IV, Fig. 5 a — d. 



1864. Myxilla Espcrii O. Schmidt, ibid., 36, foot-note. 



1880. Myxilla rosacea Vosmaer, Notes from the Leyden Mus. II, 123, 1. 



1882. Graeffe, Uebers. d. Seethierf. des. Golf, von Triest, Arbeiten aus dem zool. Inst. 



Wieu IV, 6. 

 1888. Dendoryx incrustans var. viscosa Topsent, Arch, de Zool. exp. et gen. Ser. 2, V, bis, suppl. 119, 



PI. VI, fig. 16, b. 

 1890. Dendoryx incrustans var. viscosa Topsent, Mem. de la Soc. zool. de Fr. 201. 

 1892. - — Topsent, Resultats des Campagn. scient. du Prince de Monaco, 



Fasc. II, 98. 



Intrusting (sometimes forming free branches). The surface grooved, slightly shaggy. The dermal 

 membrane thin, supported by penicillate bundles of dermal spicules. The skeleton a polyspicular reticu- 

 lation, forming partly triangular meshes, partly quadrangular, or irregular ones. Spicnla: megasclera : 

 the skeletal spicules acanthosfyli, dispersedly spined 0-178 — 0-24.""", the dermal spicules tornota, most fre- 

 quently with three-pointed ends 0-/78 — 0-22"""; microsclcra of two forms, ancorce spahiliferce 0-0/57—0-05""". 

 sign lata o-o/8 — o-oj2""". 



The specimens in hand of this species occur as thicker or thinner incrustations, especially on 

 Hydroids, and a few ones on erect Bryozoa. In the material it is found growing on Diphasia abietina, 

 Halecium sp., and Lafoea sp., and of Bryozoa on Cellaria fistulosa and Bugula murrayana. As the 

 form of the sponge chiefly follows the substratum, it becomes most frequently longish and rather 

 irregular. It always grows all round the Hydroid. Independent free branches seem, however, also to 

 be found, as the material includes some such branches, but they are torn off. The largest specimen 

 in hand has a greatest extent of ca. 57""" and a breadth of about 25 mm ; the thickness of the incrustation 

 is scarcely more than 5 mm . The mentioned free branches are more or less compressed, and have a 

 greatest breadth of 14™™, the longest one is 40'"'" long. The consistency is rather firm and somewhat 



