I2 _| PORIFERA. II. 



from the front, therefore, a little below the oblong tuberculum proper another oblong, tubercle-shaped 

 body is seen, which is the translucent, recurved end of the axis. The aire form together an oval plate, 

 and their edges are a little refolded. The plates formed by the alse of both ends continue along the 

 axis as a most frequently quite narrow ridge, and this part arches somewhat out from the axis behind, 

 so that the back side of the chela is somewhat curved, although the axis is straight. When the chela 

 is seen in profile under strong light, the axis may distinctly be followed, as it is more transparent 

 than the tooth and aire, which are seen from the edge. Then, in the first place, the inward-turned 

 terminal part of the axis is distinctly seen, next a part appearing as a hump on the outside of the 

 tooth, and finally the middle, straight part of the axis (PI. XIII Fig. 6 b). These features are not always 

 easily seen in the fully developed chela, especially as the different parts of the axis are differently 

 developed; thus the falx is rather broad, and the inward-turned terminal part grows often very thick. 

 Otherwise, with regard to length and form of this part, the chela may be rather varying; sometimes, 

 also, the axis, and consequently the whole chela, is somewhat curved. The thin ridge in the middle 

 of the cheia may vary to some degree in breadth. The length of the chela varies from 0-024— 0-03"™, 

 and its greatest breadth is ca. 0-007 — ooo8 mm . Developmental forms of the chela in all stages occur 

 rather frequently; the finest ones consist only of the axis, which, according to what has been stated 

 above, is straight and recurved at either end in such a way as to form an eye turning to one side; 

 then the aire and the plate of the tooth are formed by and by. The chelae occur both scattered in 

 the tissue of the sponge and in the dermal membrane, but upon the whole in no large numbers. 



Bowerbank's description and figures of this chela are quite incomplete; thus his figure of 

 the profile does not show the peculiar continuation of the axis, but the chela is, however, tolerably 

 recognisable, especially from the figure showing it from the front. His description, on the other hand, 

 is quite erroneous. Carter 1. c. gives a good figure of the chela seen as well from the side as from 

 the front, but in his description there are several misconceptions. Ridley and Dendy (Challeug. 

 Report, 108) say, in their description of the chela in the generic diagnosis, from the median line of 

 the posterior surface of each anterior palm there projects backwards, i. e. towards the shaft, a delicate, 

 flat fimbria-; according to this expression these authors do not seem to have seen that the question 

 is of the axis of the chela; neither is it correct, when they term the inwardly-directed process delicate, 

 flat , although, to be sure, it is frequently somewhat compressed. Also their figures of the chela, 

 especially in the species grandis, show that the process is here quite cylindrical. 



Locality: From Iceland and the Faroe Islands we have a rather considerable material. From 

 Iceland: Skagen (Gronlund), off Rodsands Bay (Hj. Jensen), Onundarfjord, depth 10 fathoms (the author); 

 Iceland, no more particular locality stated (Jap. Steenstrup, Halberg). From the Faroe Islands: 6 miles 

 N.W. of Kalso, depth 60 fathoms, Vestmansund, depth ca. 70 fathoms, 9 miles east of Nolso, depth 30 

 fathoms (Th. Mortensen) ; the Faroe Islands, no more particular locality stated (Nees, Rostrup, Miiller). 

 Seventeen larger and smaller specimens in all. 



Geogr. distr. North-England, Scotland, the Shetland Islands and the Orkneys (Johnston, Bower- 

 bank); Norway (Esper, Ehlersl. c); New Scotland, Sable Island, and the Bay of Fundy (Lambe); between 

 Cape Cod and the Gulf of St. Lawrence (Verrill). Thus the species is distributed between ca. 66° and 



