some Ii i^h Spoy'.</rs. 239 



spicules aic in buiullcs wliicli apparently V\o inoro or less 

 (il)Iiqiiely to the surface, the ends of the spici;les projecting 

 beyond the dermis. 



Spt'cnles. — (1) Acanfhoptyli. The.=e vary in size from 

 about O-lG-0-9 mm. in length by 0-00,s-()-025 mm. The 

 lonrjer of tiiese spicules have a slightly curved shaft. The 

 liead is thickly covered with short, stout, blunt spines, the 

 remaining part of the spicule being smooth. The shorter 

 acanthostyli have a curved shaft. The head is covered wilh 

 short, stout, blunt spines. Similar sj,i>i(s extend a little way 

 along the shaft. The rest of the shaft is set with recurved 

 spines. These two extremes in the acanthostyli are linked 

 together by other acanthostyli of varying lengths and of 

 varying degrees of spination, so that it is not possible to 

 divide the spicules into two gioups. (2) The dermal spicules 

 are long straight styli, minutely spined on the head. Length 

 U-5-0-75 mm. by OMJ08 mm. '(3) Jsoehfloi ijalmatrp, 0-019 

 mm. in length. (4) Toxa. These have a well-rounded 

 bend in the middle of the shaft and very slightly recurved 

 ends, which are spined. The size varies from very miuute 

 to about 0"35 mm. in length, with a maximum thickness of 

 0-003 mm. 



The sponge was dredged off the south-west coast of Ireland 

 in 250-542 fathoms. 



Eurypon ditox'y, sp. n. 



The sponge is growing in a very thin encrustation on a 

 piece of Retepora. 



The main skeleton consists of acantlio^-tyli, whicli are 

 placed veitically with their heads on the substiatum. The 

 dermal spicules are in bundles set more or less obliquely to 

 the surface. 



Spicules. — (1) Acanthostyb'. The largest of these spicules 

 are slightly curved. The shaft is smooth except at the base, 

 which is thickly covered with short blunt spines. Length 

 al)out 0'3-0-6 mm., with a maximum diameter of 0*02 mm. 

 The small acanthostyli are straight or slightly curved ; the 

 head is covered with rather strong blunt spines and the shaft 

 is thickly set along its whole length with small recurved 

 spines. Length 0-125—0-2 mm., with a maximum diameter 

 of 0*01 mm. (2) The dermal spicules are styli which are 

 often a, little crooked. The head is very minutely spined. 

 Length 0-4:-0-5 mm, by 0"005 mm. (3) LsocIkIeb palmatae, 

 0-015 mm. in length. (4) Toxa of two kinds — (a) with a 

 wide even curve and short arms ending in sharp, slightly 



