40 R. KIRKPATRICK. 



the consistence of D. setifer is soft, the colour yellowish in spirit, and the surface 

 hispidation much finer. 



The four specimens were dredged : (l) No. 48, from 10 hole, 130 fms. ; (2) No. 124, 

 near Winter Quarters, 20 fms. ; (3) No. 124b, ofi" Coulman Island, 100 fms. ; (4) No. 126a, 

 from 12 hole, 25-30 fms. 



Desmacidon maeandrina. 



(Plate XIX., figs. 4, 4a, and Plate XXIII. , figs. 4a-b^.) 



1907. Desmacidon maeandrina Kirkpatrick (10a. p. 282). 



Description. — The material consists of three sub-cylindrical fragments tapering at 

 the distal end. 



The consistence is hard and dense. The colour in spirit is dirty brownish-gray. 



The surface is fairly uniformly level, and presents flattened papillae or meandrine 

 ridges, slightly roughened at the top by projecting oxeas (best seen on side view with 

 a lens). 



The dermal membrane roofs over the grooves and spaces between the papillae 

 and ridges. The pores are mostly circular and about 95 a* in diameter. 



The small circular oscules, numerous and scattered, are about 1 mm. in diameter. 

 The skeleton is formed of a thick, main axis, consisting of rather loose, longitudinal 

 strands ; from this are given off at right angles cylindrical or lamellar bundles of loose 

 strands, which proceed to the surface and form the papillae and ridges. 



Spicules. Megascleres. Oxeas, 579 x 39 n, curved (usually) or bent at the 

 centre, with sharp, pointed ends. Microscleres. Isancorae unguiferae, 26 /x long, and 

 15 • 8 M broad, shaft strongly curved and 3 • 52 /x thick. With usually five teeth or claws, 

 about 5 '28 M long, at each end, viz., a central, single, and two lateral bifurcated teeth. 



The largest of the three pieces of this sponge is 6*2 cm. long and 16 mm. in 

 diameter. The fragments appear to be broken off from some branched specimen, and 

 I shall refer to them as branches. They are sub-cylindrical, being slightly compressed 

 in one plane. The chamber system is aphodal, the flagellated chambers (44 x 29 ju,) 

 being pyriform. There is a considerable amount of variation in the teeth of the 

 isancorae, the number varying from three to six, the most usual number being five. 



In some respects the new species resembles Desmacidon (1) ramosa (E. and D.) 

 (15. p. 107), obtained by the ' Challenger' from the Cape of Good Hope and Marion 

 Island. In both species there is a central axis of longitudinal fibres, whence fibres 

 proceed to the surface at right angles, but here the resemblance ends. In the 

 ' Challenger ' species the radiate bundles branch in a fan-like manner, finally forming 

 an almost uniform surface layer of vertical oxeas. The microscleres in D. (?) ramosa 

 are isochelae arcuatae. As in the case of D. (?) ramosa, it is doubtful whether the new 

 species, with its Raspailia-\\ke skeleton of axial and radial fibres, should be placed 

 under Desmacidon or under a new genus. 



The specimens were dredged off Coulman Island, 100 fms. 



