PORIFERA. II. 



33 



- Saville Kent's species, however, is not the only one with such spicules, and the transformation 

 of the ends of the projecting needles seems in some instances to go still farther. Tops en t (Bull, de 

 la Soc. de Fr. XXI, 1896, 149, fig. 2 a— f) has thus established a new genus, Gomphostegia ') with the 

 species loricata that is also a Mycaliue with the typical A/yfTrt/e-spiculation, but with projecting spicules 

 the outer ends of which are widened to a slightly crenelated disc and thus form a mail. In these 

 needles, which Topsent calls Exotyles», the head-end, which is turned inward in the sponge, is 

 formed in quite the same way as in the other styli in the sponge. Thus there seems to be a gradual 

 development in the formation of the ends of the projecting dermal spicules from forms where it only 

 occurs as an abnormal fact, through such where it has become a normal feature, to forms in which 

 it has been developed to an exceedingly high degree. 



Locality: Station 3, 63° 35' Lat. N., 70 24' Long. W., depth 272 fathoms ; station 54, 63° 08' Lat. N., 

 1 5 40' Long. W., depth 691 fathoms; further it has been taken at Upernivik (the Reverend Mr. Soren- 

 sen); 72 53' Lat. N., 20 36' Long. W., depth 96 fathoms (the East-Greenland Expedition 1891 — 92); 63 15' 

 Lat. N., 9 35' Long. W., depth 270 fathoms (Wandel); 62 30' Lat. N., i° 56' Long. E., depth 275 fathoms 

 (Ad. Jensen, the cruise of the < Michael Sars -, 1902). Altogether six specimens, most of which damaged. 

 The localities are situated in the Davis Strait, off East-Greenland, between Iceland and the Faroe 

 Islands, and to the north east of the Shetland Islands. 



Geogr. distr. The species has further been taken off the southern Greenland, 6i° 15' Lat. N., 

 49 11' Long. W., depth 70 fathoms, and 59 33' Lat. N., 43 25' Long. W., depth 120 fathoms (Fristedt); the 

 northern coast of Scotland and the Shetland Islands (Bowerbank); the Kara Sea, depth 65 fathoms 

 (Levinsen); the eastern coast of Canada, depths 75 and 80 fathoms (Lambe); off the north-west coast 

 of Spain, depths 71, 133, and 160 fathoms, off New Foundland, depths 673 and 82 fathoms, and at the 

 Azores, depths 69 and 185 fathoms (Topsent). Thus the species is in the mentioned seas distributed 

 about from 73 to 40 Lat. N., with a bathymetrical distribution from 65 — 691 fathoms. 



Remarks on the species Mycale placoides and lingua. These two species are exceedingly closely 

 related to each other. The external form, the pore furrows, the structure of the skeleton, and, partly, 

 the spiculation show great conformity. Among the distinguishing characters the most important one 

 is the presence of particular dermal spicules (the spicules that are spread in a peuicillate way and 

 carry the dermal membrane) in placoides, while in lingua these spicules are of the same form and 

 size as the other spicules of the skeleton. It is especially this character that is of value as a sure 

 distinctive mark between the two species. Further the tooth in the larger end of the chela is broader 

 in lingua than in placoides, as is seen from PI. XI, fig. 5 e compared with fig. 6 c. Then the styli are 

 upon the whole longer and thicker in lingua than in placoides, and finally the sigmata are also most 

 frequently larger in lingua than in placoides. 



If I have determined the two species as placoides and lingua, I must remark that Carter 



J ) In the work by Topsent from 1904 (p. 202, PI. XIV, fig. 15) quoted in the list of synonyms he has acknowledged 

 that Gomphostegia is synonymous with Rhaphidothcca. 



The Ingolf Expedition. VI. 2. 5 



