I 8 PORIFERA. II. 



iu 1 1' Long. W., depth 645 fathoms; station 53, 63° 15' Lat. N., 15° 07' Long. W., depth 795 fathoms; sta- 

 tion 54, 63 08' Lat. N., 15° 40' Long. W., depth 691 fathoms; station 55, 63' 33' Lat. N., 15 02' Long. W., 

 depth 316 fathoms; station 73, 62° 58' Lat. N., 23 28' Long. W., depth 486 fathoms; station 81, 6i°44' 

 Lat. N., 27 00' Long. W., depth 485 fathoms; station 85, 63 21' Lat. N., 25° 21' Long. W., depth 170 

 fathoms; station 92, 64 44' Lat. N., 32 52' Long. W., depth 976 fathoms; station 93, 64° 24' Lat. N., 35 14' 

 Long. W., depth 767 fathoms; station 95, 65 14' Lat. N., 30° 39' Long. W., depth 752 fathoms; station 96, 

 65° 24' Lat. N., 29° 00' Long. W., depth 735 fathoms; station 98, 65° 38' Lat. N., 26 27' Long. W., depth 138 

 fathoms; station 115, 70° 50' Lat. N., 8° 29' Long. W., depth 86 fathoms; station 143, 62 : 58' Lat. N., 7 09' 

 Long. W., depth 388 fathoms (bottom temperature -=- o°4 C). It has further been taken in the Den- 

 mark Strait at 65 3 29 Lat. N., 28 25' Long. W., depth 553 fathoms (Ryder), and at 63 15' Lat. N., 9 35' 

 Long. W., depth 270 fathoms (Wandel). Finally it has been taken at 64 56' Lat. N., 11° 48' Long. W., depth 

 115 fathoms, and 62 30 Lat. N., i° 56' Long. E., depth 275 fathoms (Ad. Jensen, the cruise of the Michael 

 Sars 1902). The greatest number of specimens were taken at station 95. The localities are situated 

 over about the whole Ingolf-territory, iu the Davis Strait, the Denmark Strait, south of Iceland, at 

 Jan Mayen, between Iceland and the Faroe Islands, and at the coast of Norway. 



Geogr. distr. The Barent Sea, at depths of 145, 170, 192, and 220 fathoms (Vosmaer 1. c); Fri- 

 stedt I.e. has it from north of Spitsbergen, 79° 47' Lat. N., n° 15' Long. E., depth 100 fathoms, and at 

 South-Greenland, 59 33' Lat. N., 43 25' Long. W., depth 120 fathoms. The species is, accordingly, widely 

 distributed between ca. 50 Long. W. and 50 Long. E. and between ca. 59° and 8o° Lat. N. Its bath} - 

 metrical range is from 86 fathoms (at Jan Mayen) to 976 fathoms (the northern Denmark Strait). The 

 species seem to be a native on bottom with positive temperature; it was taken, however, at station 

 143 with a temperature of -^ o°4 C. 



2. I. dubius Arm. Hans. 

 PI. VI, Figs. 2—5. PI. XVII, Fig. 4 a— e. 



1885. Reniera dubia Armauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadce, 6, PI. II, 



fig. 1, PI. VI, fig. 7. 

 1887. Esperia Pattcrsoni Fristedt (non Bow.), Vega-Exp. vetensk. Iakttag. IV, 448. 



The form most frequently branched, more or less free or somewhat coalesced, cylindric or flattened 

 branches issuing from a base ; sometimes the sponge is more irregularly lobate or forms incrustations. 

 The surface smooth or very slightly shaggy. The dermal membrane an easily separable, thin film, pro- 

 vided tail It a reticulation of dermal spicules, and supported by penieillatc bundles of such spicules. Oscula 

 scattered. The skeleton a close, irregular, partly polyspicular, partly unispicular reticulation. Spicula: 

 Megasclera : the skeletal spicules acanthosfyli 0-208 — 0-274""", the dermal spicules tylota to strongyla with 

 spiued ends o-jg — 0-25"""; microsclera of two forms, anisochelce palmatce of the Jophou-type 0-0/7 — o-oji""". 

 bipocilla 0-007 — o-oio""". 



This species may, according to its mode of growth, have a somewhat varying appearance. 

 It grows especially on Hydroids, and is found on many different species, and on erect Bryozoa. It 

 may then form common, more or less thick incrustations, the thicker ones may be irregularly cushion- 

 shaped, or they send off more or less stubby lobes. By far most frequently, however, it forms more 



