PORIFERA. I. 



93 



cimens; station 92, 64' 44' Lat. N., 32 52' Ivong. W., depth 976 fathoms, fragments of a larger specimen; 

 station 95, 65' 14' I^at. N., 30- 39' Long. W., depth 752 fathoms, two qnitc small specimens and a few 

 fragments; station 96, 65' 24' Lat. N., 29° 00' Long. W., depth 735 fathoms, two .smaller specimens; it has 

 fnrther been taken on the East-Ckeenland expedition 1891—92 on 65" 39' Lat. N., 28° 25' Long. W., depth 

 553 fathoms, one specimen. These stations are all sitnated in the Denmark .Strait, excepting station 53 

 that is off the sonth coast of Iceland. 



Geogr. distr. Of this sponge hitherto only two specimens have been known, one taken at Scot- 

 land (the original specimen of Bowerbank) the other in the English Channel at Luc (Topsent). Un- 

 fortunately no depth has been given for either of these localities. 



3. D. hamifera n. sp. 

 PI. VII, Figs. 4— 6, PL XVII, Fig. I a— 1. 



Leaf:'- or fuiuirl-sliapcd. Thr sur/acr ivitli small conical procissrs foriiitd h\ tlic projecting fibres. 

 The dermal mcmhranr l/iiii^ only pro^nded 7villi microsclera. Osciila scailerrd. Thr skeleton consists of 

 poiucrjitl polyspiciilar fibres brniiehing from the base up throtigli the sponge, and connected by tratisiu-rse 

 anastomoses. Spongin is foniid ceinenfing the spicules., but only to a rattier small degree. Spicula : 

 Mcgasclera styli o'/j — r^6"""; microsclera sigmata of t7vo sizes, large ones 0/ a pectiliar form, most fre- 

 ijuently as dragmata o-o8 — o-io/""". small ones 0-014 — o-02i"""; rhaphides as trichodragmata of tivo sizes, 

 long, hair-liki' ones o-i_^ — o-i6""", short ones 0-042 — 0-06"""; comma fa o-oii — 0-014""". 



This species is of a quite similar form and structure as the preceding one. The specimens in 

 hand have an erect, leaf-shaped form; a single one shows a short, thick stalk which has been attached, 

 and which has at the top the remains of an open funnel (PI. VII, fig. 5). None of the specimens, 

 however, are quite undamaged, so that there may be some doubt whether the species is always funnel- 

 shaped, or perhaps also may be leaf-shaped. The largest specimen, a somewhat concave-convex leaf, 

 has a height of 12"=™, and a similar breath; the thickness in the middle of the leaf is about 20""". The 

 thickness is greatest below where the .sponge has been attached, and decreases towards the upper 

 edge. The other specimens are all somewhat smaller, also leaf-shaped, but most of them are a little 

 arcuate, so that the probabilit\- is that the sponge is funnel-shaped. A single fragment is attached to 

 a stone. The consistency is rather firm, hard down towards the place of attachment. The colour (in 

 spirit) varies between light yellow and light gra)-. The dermal membrane is also in this species sup- 

 ported h\ the ends of the fibres, and so the surface shows the same kind of small processes as in 

 the preceding species. The dermal membrane is otherwise onh' kept here and there in a few of the 

 specimens. It show.s, at all events in some places, a quite peculiar structure. When viewed under a 

 lens, it shows a network resembling a network of spiculo-fibres, as for instance in H.panicca; but under 

 higher magnifying powers it is seen that the network is made bj- the formation of thicker strings in 

 the skin inwardly; the network incloses roundish or oval thin-skinned fields, and in these fields the 

 pores are hing in different numbers. In the strings of the network some roundish or fusiform cells are 

 seen filled with refringent granules (cellules spheruleuses Tops.). This structure of the skin, however, 

 is not found ever>where, the skin in other places appearing as a simple thin membrane without any 



