286 Mr. E. Kirkpatrick on the Monaxonellida 



Iloplahilhara Dendy'i *, 



Sponge in form of a small cusliion, attached by a narrow 

 base. Surface smooth to the naked eye. Colour pale brown 

 in spirit. Consistence, hard externally, soft within. Flagel- 

 lated chambers 32*5 /i in diameter, spheroidal, eurypylous. 



Skeleton witii ])rotective armour formed by gigantic 

 spheroidal heads of exotyles, the exotyles being arranged as 

 radiating bundles in form of inverted cones, with the apices 

 a little below the cortex ; with scattered strongyles. 



Spicules. — Megascleres : exotyles, with the heads a little 

 inclined to the long axis of the spicule, the proximal end (in 

 the interior of the sponge) rounded, the distal end swollen 

 into large spherical heads, with short cylindrical spines 

 covering the distal three-fourths of the head. Total length 

 358 fi, the shaft enlarging in diameter from 6*5 fi at the 

 proximal end to 16 yu, just below the head. Head 55 /j, in 

 diameter; cylindrical denticles 1*76 to 3*52//, in height, 

 with finely denticulate edge, and with cup-like depression at 

 the summit. 



Strongyles straight, fusiform, smooth, 467*5 yu, long, 9*75 /x 

 in diameter at centre, 6'5 yw. in diameter at ends. 



Microscleres : placocheles, fimbriated, 84"5 /x long, 29 25 /j, 

 broad ; length of tooth 37*75 yt*. 



Sigmata very small, slender, C-shaped, 8"8/x. long, 5*28 yu, 

 broad, '9 fi thick. 



The minute spheroidal or cushion-shaped specimen was 

 2*2 mm. in height and 3 mm. in horizontal diameter; it was 

 growing on the side of an Alcyonarian creeping over a 

 branched Cellepora. No pores or oscules were discernible. 

 The under surface, which was narrowed to the point of 

 attachment, was paler in colour than the upper. 



The new genus is closely related to the Mycaline genera 

 Rhaphidotheca and Guitarra, to the former by its exotyles, 

 and to the latter by its iimbriated placocheles. 



The distal knobs of the exotyles of jR. Marshall- 1 JalUi, 

 Kent, 49 yu. in diameter, are smooth and spherical, and those 

 oi R. rhopalophora, Schmidt {R. offiniSj Carter), are 104/* 

 long and 30 yu. broad, and club-shaped. Lundbeck regards 

 these two species as probably identical, and certainly the 

 differences are slight. 



Locality. Winter Quarters, 130 fath. 



Gellius fimhriatus, sp. n. 

 Sponge in form of a thick triangular cake, or conico- 

 cylindrical. Texture soft, easily broken. Colour in spirit 

 p)ale buff. 



* Named in liouour of Professor Dr. A. Dendv. 



