PORIFERA. III. u 



We have a specimen of this species which I at first thought was a distinct form on account 

 of its smaller spicules, but which on closer examination proved to be a very young specimen of 

 appeiidiculatuiii. The specimen is globular, with a single fistula, and very small, about 3 mm in 

 diameter, and thus not larger than the examined embryo. It shows quite the same structure as the 

 full-grown specimens; it has a distinct dermal layer with subdermal cavities below, and also distinctly 

 shows the skeletal structure of the inner body. The specimen is interesting in showing, that such small 

 specimens may have considerably smaller spicules than the grown specimens. It is yet no doubt only 

 the very small specimens which show in this respect any difference worth mentioning, and it is certainly 

 the case, that they very soon get spicules of the size normal to the species. The examined specimen 

 has probably just left the mother-sponge. The megacleres do not reach beyond 0-41 mm , the chelse 

 are crc^o' 1 "", and the sigmates are of the same sizes as in the full grown sponge. It is interesting to 

 notice, that the chelae in this specimen are intermediate in size between the cheke in the embryo and 

 those in the grown sponge. The relatively long and fine megascleres in the embryo seem here to be 

 replaced by shorter but thicker spicules. 



Locality: Station 78, 6o c 37' Lat. N., 27 52' Long. W., depth 799 fathoms, about 29 more or less 

 damaged specimens; station 90, 64 45' Lat. N., 29 06' Long. W., depth 568 fathoms, two specimens and 

 some loose fistula; ; further at 6i° 15' Lat. N., 9 35' Long. W., depth 478 fathoms, a very small specimen 

 (The fishery investigation steamer "Thor"). The localities are situated on the eastern slope of the 

 Reykjanaes Ridge, in the Denmark Strait and West of the Faroe Islands. 



Gcogr. ciistr.: Carter had the species from the west coast of Ireland, depths 808 and 109 fathoms. 

 (Porcupine). 



2. H. physa O. Schmidt. 

 PL I Figs. 12—13, PI. IV, Fig. 3. 



1875. Dcsiuacidon physa O. Schmidt, Jahresber. der Conim. zur wissensch. Uuters. deutsch. Meere in 



Kiel fur 1872—73, 118, Taf. I. Fig. 8-9. 

 1887. Cornulum ascidioidcs Fristedt, Vega Exp. wetensk. Jakttag. IV, 495. PI. 25, figs. 1 — 2, pi. 29, fig. 21. 

 1903. Histodcrma physa, Arueseu. Berg. Mus. Aarbog 1903, 16, Taf. II, Fig. 5, Taf. Ill, Fig. 9. 

 1903. — — , Thiele, Arch, fur Naturgesch. Jahrg. 1903, 385, Taf. XXI, Fig. 16 a— b. 



1909. — — , Lundbeck. Meddel. om Gronland, XXIX, 443. 



Roundish or more irregular, sometimes somewhat erect, attached with a broad base: provided 

 with one or a couple of conical spouts. Surface smooth. The sponge surrounded by a solid, but not 

 thick, bladdery derma/ lexer. Oscula at the summit of the conical spouts, the pores on the side of these. 

 The dermal skeleton formed of close-lying spicules parallel to the surface. The skeleton of the inner 

 body consisting of fine fibres and bundles of spicules, running irregularly, but at the surface parallel 

 with this; without transverse fibres. Spicula: Megasclera strougyla with intermediates to subtylota, 

 o-jjo—o-8p mm ; microsclera of two forms, chela arcuatce crojs — o-oj<S'""", trichodragmata <ri/—u-i2""". 



This species has a shape mainly as described by Schmidt. It consists (on account of con- 

 traction or destruction of the inner bod}) of a bladder, formed of the dermal layer. This bladder may 



2* 



