12 



E. ARNESEN. 



[REP. OF THE "MICHAEL SARS" NORTH 



It is to be noticed, that Topsent's specimens have 

 no basal tuft nor even a trace thereof, while among the 

 3 specimens from the "Michael Sars" expedition the one 

 has a tuft 15 cm. long, and the second a hole at the 

 base, from which most probably a tuft has been torn out; 

 the third specimen is only a small piece of the body. 

 Besides this, the "Michael Sars" specimens are larger 

 than those of Topsent, the one with basal tuft, being 

 11 cm. long with a diameter at the margin of 8.5 cm., 

 and the other one 8 cm. in length with a diameter at 

 the margin of 7 cm. 



Spiculation. As to the spiculation I have observed, 

 besides the ordinary smooth diacts and the middle sized 

 hexacts. the characteristic m icro-oxyhexacts with 

 straight and prickly rays, 0.110 mm. long — thus somewhat 

 longer than those measured by Topsent, which were 

 only 0.080 mm. (80 /»). Further there are three kinds of 

 amphidiscs, which agree well in form and size with those 

 of H. infundibulum — though also somewhat longer than 

 those measured by Topsent: macram phi discs with a 

 nearly hemispherical umbel and faintly echinated shaft, 

 generally without central nodul, length 0.222 mm. — 0.296 

 mm.; mesamphidiscs with a more bell-shaped umbel 

 being 0.081 mm. — 0.120 mm. long and micramphidiscs, 

 0.022 mm. — 0.037 mm. long. As to the pinnules 1 find 

 those of the "membrane criblee du cloaque" correspon- 

 ding well with Topsent's description and figure (pi. 8, 

 fig. 3). My measurements give for the unpaired ray 

 0.120 mm.— 0.222 mm. and for the paired ones 0.040 

 mm. — 0.055 mm. The other, more bushy kind of pinnules 

 in my specimens seldom reach the length indicated by 

 Topsent — thus the unpaired rays rarely exceed 0.200 

 —0.300 mm. and the cruciate ones, often thickly spined, 

 are of variable length (from 0.045 mm. to often nearly 

 the lenght of the distal ray). Besides these spicules there 

 are in the basal pad strong tetracts and hexacts with 

 rough echinated rays. Both agreeing well with those in 

 H. thomsoni, and especially H. thomsoni var. exigua 

 (26, fig. 15 & 17, pi. XXXIV). 



The diacts of the basal pad have often echinated 

 ends. The basal tuft consists of few, only 12 — 16, rather 

 thick spicules, the ends of which are all broken, so that 

 no anchors could be observed. 



The presence of a basal tuft, and the approximation 

 as regards the measurements of the spicules to those of 

 H. Thomsoni, support Topsent's suggestion (41, p. 32), 

 that H. infundibulum may represent only a variety of 

 H. Thomsoni. 



Geographical distribution: H. infundibulum has 

 been taken off the Azores (1372 m.) and in the Bay of 

 Biscay (1710 m. depth). 



The "Michael Sars" specimens come from the 

 Spanish Bay (35° 32' 7" T W); 1215 metres. 



Pheronema grayi Seville Kent. 



(PI. I, «g. 9). 



Vide litter: 12, p. 182, 34, p. 29, 41, p. 29). 



St. 23. 2 specimens (denuded). 



St. 24. 20—30 specimens (denuded). 



St. 41. 2 specimens. 



Unnamed locality 11 dried specimens. 



Though all the specimens from the "Michael Sars" 

 Expedition are denuded, having lost most of their pros- 

 talia lateralia and even often the basalia, they seem to 

 be identical with Pheronema grayi Saville Kent, to 

 judge from the globular form (the largest specimens me- 

 asuring about 13 cm. >< 13 cm. and 13 cm. X 11 cm., 

 the smaller ones 7 cm. X 7 cm.) and the funnel-shaped 

 cloacal aperture (diam. 3 cm. — 4 cm.). Though, it is to 

 be noticed that one of the two specimens obtained at 

 station 41 decidedly shows a cylindrical form (7.5 cm. X 

 5.5 cm.) thus resembling Ph. carpenteri. The prostalia 

 pleuralia have a scattered disposition, while the prostalia 

 basalia undoubtedly show a tendency to be grouped in 

 bundles; the basal tuft measures 15 cm. The marginal 

 fringe is rather defective, while the zone, 2 cm. below, 

 is as a rule pretty well preserved. 



As to the spicules they agree well with the descrip- 

 tion and figures given by Saville Kent (pi. LXIII, 12) 

 and by Topsent (pi. VII, fig. 9, p. 29, 34, and pi. VII, 

 fig. 2, p. 29, 41). 



Geographical distribution: Of the seven recog- 

 nised species of Pheronema three are known from the 

 Atlantic (Ph. grayi, Ph. annce, and Ph. carpenteri). While 

 the two lastnamed species are from the western Atlantic, 

 Ph. grayi has been recorded from off Setubal, Portugal, 

 (depth 1098 m.) and was met with in profusion at the 

 Azores at different stations between 793 and 1557 m. 



Tethyopsillst zetlandica (Carter). 



(PI. VI, fig. 6). 



Vide litter: 15, p. 31. 



St. 24. (NB! There is some doubt wether the spe- 

 cimens are from st. 24 or 41). Two specimens. 



One specimen is spheroidal in shape with a diameter 

 of 4 cm., the other oblong, 4 cm. X 6 cm. Surface 

 rather abraded, though showing a dense hispidity. Root- 

 tuft about 5 cm. long— present only in the oblong spe- 

 cimen. Colour in spirit light yellowisch brown. Cortex 

 2 — 3 mm. thick. 



Spicula: Megasclera: Cortical oxea. fusiform, 

 bent or straight with long and evenly tapering ends, about 

 1.7 mm. long by 0.030 in the middle. Somal oxea, 

 anisoactinate, nearly double the size of those in the typical 

 form. Protriaene, rhabdome 8.5 mm. long by about 

 10.050 mm. in the proximal part and tapering Irom the 



