4 8 



PORIFERA. III. 



running parallel with the underlayer; further there are bundles stretching obliquely up to the surface, 

 and at the surface there are again bundles or fibres present running more or less parallel with it; 

 besides, there are also found scattered spicules at the surface. The bundles are often rather thick. 

 The dermal spicules form thus the greatest part of the whole skeleton. The main skeleton consists of 

 acanthostyli with their head-ends on the substratum; they do not reach beyond the surface. Spongin 

 seems to be found at the base, but only to a very slight degree. 



Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli; they are straight or 

 slightly curved and have a rather small head-swelling; the apex is even and long. The spinulation 

 is somewhat slight, as commonly the largest spines are found at the head-end; in the longer styli 

 the spines become very small outwards, and the outer part of the spicules is smooth; the smaller 

 styli are spined in the whole length, and the spines are generally larger. The styli vary much in 

 size, but they are not divided into two groups. The length is 0-119 '53 mm an ^ the diameter of the 

 head 0-014 0-027 mm . 2 - The dermal spicules are strongyla, they are straight or, more rarely, 

 slightly curved, and they are slightly fusiform. The ends are not uniform, one end is rounded and 

 sometimes slightly swollen, the other end is thinner and rounded or with a stubby point. The length 

 is 0-24 0-357 nim and the diameter about 0-004 O'OO57 mm . The strongyla may be slightly polytylote on 

 the middle part. b. Microsclcra; these are chelse arcuatse; they have a curved shaft, the curvature 

 of which is distinctly situated in the middle of the shaft; the end-parts occupy nearly always less 

 than a third part of the length of the chela; the tooth is broadly elliptical, the alse are lobe-shaped, 

 of the same length as the tooth. The length may vary somewhat in the same individual and still 

 more in various individuals, it is in all 0-027 0-040""", an ^ the diameter of the shaft is 0-0028 O'oo4 nini . 

 The chelse occur rather numerously in the dermal membrane, and they seem exclusively or at all 

 events chiefly confined to it 



Locality: Station 25, 63 30' Lat. N., 54 25' Long. W., depth 582 fathoms; station 28, 65 14' Lat. N., 

 55 42' Long. W., depth 420 fathoms; station 83, 62 25' Lat. N., 28 30' Long. W., depth 912 fathoms; 

 station 97, 65 28' Lat. N., 27 39' Long. W., depth 450 fathoms; further it has been taken at 64 42' 

 LaLN., 27 43' Long. W., depth 426 fathoms (Wandel), 62 29' Lat. N., 5 17' Long. W., depth 160 fathoms 

 (Ad. Jensen, the cruise of "M. Sars" 1902) and 63 05' Lat. N., 20 07' Long. W., depth 295 fathoms (The 

 Fishery investigation steamer "Thor"). Nine specimens in all. The localities are situated in the 

 Davis Strait, the Denmark Strait, South of Iceland and West of the Faroe Islands. 



6. H. curvichela n. sp. 

 PL VI, Fig. 2. 



Intrusting; surface diffusely hispid. The main skeleton not dense. Spicula: megasclcra;. the 

 skeletal spicules acanthostyli with no distinct or only a slight head; the small spined in the whole length, 

 the larger less spined until only spined at the base; the styli divided into t^vo groups, large 0-53 <r8o""", 

 small 0-707 o-jo mm ; the dermal spicules strongyla, slightly polytylote, <rj2 o'fo""" ; microsclera chrlcr 

 arcuate, strongly curved, 0-031 



Of the specimens of this species one grows on a stone together with //. Koclilrri. baculifcra 



