PORIFERA. III. 



13 



the shaft not much curved with the curvature mainly King in the middle, the ahe and tootli are 

 of the same length, the tooth narrowly elliptical with a long, narrow tuberculum. In all the length 

 is between 0-035 all( i 0-058 n,m with a diameter of the shaft of 0-0028— 0-007 mm , ,jnl tl,L ' chelae also vary 

 somewhat in different individuals, e. g. 0-035— 0-043 mm , °'°45 — 0*054 mm and 0-050—0-058""", and the 

 diameter of the shaft may be 0-0028— 0-004'" m and 0-004— 0-007""". 2 - The trichodragmata; the 

 single rhaphides are exceedingly, nearly immeasurably fine, less than o-ooo6'" ra , the bundles have a length 

 of o-ii— 0-12 mm and a thickness of about 0-021— 0-035 m,n , the single rhaphides were measured to a 

 length of about o-io""". The rhaphides seem not to occur singly, but only in bundles. The chelae 

 occur both in the dermal layer and in the inner body, here rather numerously, the trichodragmata 

 are mainly seen in the inner body at its surface. 



The identification of this, otherwise rather characteristic species, is certain, as I have examined 

 a piece of one of Schmidt's type-specimens. Also of the Cornulum ascidioides Fristedt I have examined 

 a type-specimen and thus been able to decide, that this is the present species; Fristedt has over- 

 looked the trichodragmates, and the length, 0-07 '" m , he gives for the chela; is erroneous, as in his 

 type-specimen I found the chelae to be of a length of 0058'"'". 



Locality. Station 6, 63 43' Lat. N., 14 34' Long. W., depth 90 fathoms; station 16, 65 43' Lat. X., 

 26 58' Long. W., depth 250 fathoms; station 89, 64 45' LaL N., 27 20' Long. W., depth 310 fathoms; 

 station 94, 64°56' Lat. N., 39° 19' Long. W., depth 204 fathoms; station 97, 65 28' Lat. N., 27° 39' Long. W., 

 depth 450 fathoms; further the species has been taken at 62 26' Lat. N., 4° 49' Long. \V., depth 228 

 fathoms and 62° 53' Lat. N., 9 06' Long. W., depth 245 fathoms (Ad. Jensen, the cruise of "M. Sars" 19021; 

 seven specimens or fragments in all. The localities are situated in the Denmark Strait and between 

 Icelands and the Faroe Islands. 



Geogr. distr. The species has earlier been taken South-west of Bukenfjord, Norway, depth 106 

 fathoms (Schmidt), 0stfjord at Bergen, depth 292 fathoms (Arnesen), and in Baffin Bay 68° 08' 

 Lat. N., 58 47' Long. W., depth 169—183 fathoms (Fristedt). The southern limit of the species is thus 

 at 59° Lat. N. 



Histodermella now gen. 



Sponges which in appearance and structure arc like Histoderma; the consistency more or less 

 bladder-like. The shape varies from round or roundish forms through longish to tube-shaped, often slightly 

 branched forms; the body provided with shorter or longer tube-shaped fistula, or with shorter papilla. 

 The sponge surrounded by an outer, very solid derma/ layer with close-lying spicules parallel to the 

 surface. The skeleton of the inner body consisting of scattered spicules or irregular fibres, sometimes 

 more regular at the surface, but not forming a reticulation. Spongin not present. Spicula: megasclera 

 of hvo forms, but these are intermingled so that the spicules are the same in the dermal layer and the 

 inner body; the megasclera are diactinal, of the two forms one is smooth, the other spined; the smooth 

 megasclera arc tylota or strongyla, sometimes with the ends finely spined. the spined megasclera are 

 acanthoxea or acanfhostrougyla. Microsclera may vary somewhat in composition . the characteristic 

 microsclera are choice arcuatic. to these are added sigma/a. and further trichodragmata may occur and 

 besides (natalensis) curious spined bodies (transformed cliche .' or forcipes?). Microsclera may be quite absent. 



