PORIFERA. II. 15 



or almost without any beginning of the ake or of the plate of the tooth. The developmental forms 

 have the same length or about the same length as the fullgrown ones. The chela; are found through- 

 out the sponge, and in no small number in the dermal membrane. 



Locality: The Faroe Islands, 9 miles to the east of the Nolso revolving light, depth ca. 30 

 fathoms; 6 miles north and to west of Kalso, depth 60 fathoms (Tli. Mortensen); the Westmann Islands 

 (Saemundsen). Six specimens or fragments in all. 



Grogr. distr. The species is hitherto known to the south as far as the Channel, Guernsey 

 (Bowerbank), Luc and Le Portel (Topsent); farther north it has been taken off Bohuslan (Fristedt), and 

 in the Cattegat on depths from 6 l! , to 10 fathoms (Levinseu). 



3. E. sp. (?Alderi Bow.) 

 PI. VIII, Fig. 3 a— c. 



We have a quite small specimen of an Espcriopsis-species sitting on a worm-tube, which 

 specimen has a skeletal structure similar to that of the preceding species. The primary fibres have a 

 few more spicules alongside each other, and they also pierce the dermal membrane, so that the sur- 

 face is shaggy; but the spicules are different. Megasclera are styli, most frequently rather strongly 

 curved and with an evenly tapering, rather long point. Their length is between 0-38 and o-44 mm , and 

 the thickness is about o-oi mm . Microsclera are isochelse palmatae of a similar structure as in the pre- 

 ceding species, but they are straight or almost straight; besides they are a little larger, their length 

 being 0-025 — o-028 mm and the breadth ca. ooy" 1 '". Also of these chelae developmental forms were found 

 of the same appearance as in the preceding species. 



The chelae of this species show a peculiarity, which, however, is not found in all of them, and 

 which may be more or less marked where it is found. It consists in the fact that the recurved final 

 part of the axis, which must be supposed to run along the middle of the tooth, some way down the 

 tooth bends off from it inward, and, when the chela is viewed from the side, appears as a projecting 

 point or knob on the inside of it ; when the chela is viewed from the front it appears through the tooth 

 as a little tubercle close to the edge. As mentioned, the feature, hovewer, is far from being a constant 

 one, in some of the chelae it is not found, and it may also be found singly in other species. — Lambe 

 (Proceed, and Transact, of the Roy. Soc. Canada, X, 1893, Sec. IV, p. 68 seq.) has described four Espcriopsis- 

 species, which, to judge from the figures (no mention is made of it in the text), have chelae, in which 

 the mentioned structure is strongly marked. As is well known, the same structure is again found in 

 the chelae of the genus Homoeodictya, and this genus or subgenus has been established just on this 

 structure. The Esperiopsis-species showing this structure of the chela-, to be sure, are closely allied, 

 but as the character does not seem to be a constant one, it can here scarcely be used as a generic mark. 



Locality: St. 127, 66° 33' Lat. N., 20 05' Long. W.; depth 44 fathoms. 



Geogr. distr. E. Alderi Bow. is from Northumberland. 



Note. The Esperiopsis-species placed by Bowerbank under the genus Isodictya, appear to 

 be closely allied, and there is a great probability that Bowerbank has established too many species, 

 but it will not be possible, without a close examination of the type specimens, to unravel the species; 



