48 



PORIFERA. I. 



united by a not copious mass of spougin. Outside the skeleton some finer and shorter needles are 

 found in tlie tissue. 



Spiciila are oxea; most frequentl}- the}- are evenly curved; more rareh- the curve ma}- be 

 sharp; the length varies between o-i6— 0-178'^"', the thickness varies comparatively much, from 0-005— 

 o-oio™™. Shorter and finer needles are found in small numbers. 



Locality: There is in the collection only one specimen of the species from Se}-disfjord in Ice- 

 land (H. Jonsson), from a depth of 7—8 fathoms. 



II. R. calamus u. sp. 

 PI. V, Figs. 1—2, PL XI, Fig. 15 a, b, Fig. 16. 

 Erect, tiihdar, or formed like a thick-ivalled cylinder. The dermal membrane thin., zvithotit spi- 

 cules; the surface finely shaggy? The skeleton consists of a rather regular netivork of primary fibres 

 running towards the surface, and mostly single transverse spicules, placed irregularly, connecting the 

 fibres. Spicula oxea, dividing into two different groups of sizes; the larger ones evenly tapering and 

 evenly curved, o-2j^ — 0-268"""; the smaller ones more bent, o-ioy - o'/j""". 



Of this species we have one specimen, formed completely like a cylindric tube. The specimen, 

 however, has been broken in the middle, and both ends are damaged or broken, so that it cannot be 

 decided, in what wa^■ the sponge has been attached, or how the upper end has been formed; on the 

 other hand, the sponge, no doubt, has been erect, and the form has probably been as a cylinder with 

 a simplv rounded upper end. The length of the specimen in its present state is 55""", and the breadth 

 20™'". The colour (in spirit) is light gray-brown. The cousistenc}" is comparatively hard and tirm. The 

 surface^ as in most A^rw/rw-species, seems to be fineh- shagg}- from the projecting ends of the primary 

 fibres; I have not been able, however, with certaint}' to decide this feature, as the dermal membrane 

 has onlv been kept in few places. When the sponge was taken up, it was filled, to an exceedingly 

 high degree, with mud and extraneous sponge spicules'). The dermal membrane, where it is kept, is 

 thin, transparent, and without sjDicules. The pores are found in the dermal membrane as round or 

 oval openings; they have been measured to a size of from 0-017""" to about 0-3'"'", most frequently 

 they are about o-os'"'". Through the middle of the sponge a c}lindric canal runs, of equal width in 

 its whole length, which canal must be regarded as an oscular canal; but the upper end being damaged 

 the striicture of the mouth of the tube, the osculum, cannot be decided. The canal has a width of 

 5-5'""', and the thickness of the wall is between 7 and S'"'". The excurrent canals open into the os- 

 cular canal; their course through the wall of the sponge is obliquely upward and inward; the openings 

 are varying in size; the largest ones are ca. 1-5""". The larger openings lie here and there in trans- 

 verse or oblique series; but otherwise no distinct arrangement is found. From these ojjenings the 

 canals branch off into the wall of the sponge, and end in the many small subdermal ca\-itie.s, which 

 are found close to each other on the outside of the sponge. 



The skeleton. From the inside of the oscular tube, fibres rim ver}- regularly arcuatel}- upward 

 and outward towards the surface on which they are about perpendicular. These primar}- fibres are 

 polyspicular, and consist most frequently of 3 — 6 spicules, and sometimes of still more, alongside. 

 ■) This filling, however, had probably taken place in the trawl. 



