some LiiJi Sponges. 239 



spicules are in bundles wliicli apparently lie more or less 

 obliquely to the surface, the ends of the spicules projecting 

 beyond the dermis. 



Spicules. — (1) Acanthostyli. These vary in size from 

 about 0-16-0-9 mm. in length by 0-008-0-025 mm. Tlse 

 longer of these spicules have a slightly curved shaft. Tiie 

 head 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 with 

 short, stout, blunt spines. Siniilar spiues 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 groups. (2) The dermal spicules 

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

 0-o-0'75 mm. by 0-008 mm. "^ (3) Isochelaj palmatse, 0-019 

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

 bend in the nsiddle of the shaft and very slightly recurved 

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

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

 0-003 mm. 



The s|)onge was dredged oflp the south-west coast of Ireland 

 in 250-542 fathoms. 



Eurypon ditoxa^ sp. n. 



The sponge is growing in a very thin encrustation on a 

 piece of Retepora. 



The main skeleton consists of acanthostyli, which are 

 placed vertically with their heads on the substratum. The 

 dermal spicules are in bundles set more or less obliquely to 

 the surface. 



Spicules. — (1) Acanthostyli. 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 

 about 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 O'Ol mm. (2) The dermal spicules are styli which are 

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

 Length 04-0-5 mm, by 0'005 mm. (3) Isochelse palmatse, 

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

 wide even curve and short arms ending in sharp, slightly 



