BY E. F. HALLMAXN. 637 



at the apex, and thus exhibit a feature which might be looked 

 upon as differing essentiahy only in degree of development from 

 the furcation of the cladostrongyla of T. faniformis. Hence I 

 am strongly inclined to think that Thrinacophora is of "Ectyo- 

 nine" origin, and that its correct position is in the Desmacidonidse. 



Genus Dragmatyle Topsent. 



Definitiov . — Axinellidfe(?) of encrusting liabit, with a main 

 skeleton consisting of long smooth tylostyli disposed vertically, 

 with their heads based on the substratum, and a dermal skeleton 

 formed of smooth diactinal raegascleres disposed tangentially. 

 Microscleres trichodragmata. 



Type-species, D. lictor Topsent(53). 



The systematic position of Draymafyle, like that of Thrina- 

 cophora, is uncertain. The character of the skeleton (in the 

 single known species) affords ground for the view that the genus 

 is of "Ectyonine" derivation; and this view is further supported 

 by the existence of two species of thinly encrusting habit — the 

 so-called Hymeraphia viridis Topsent(46), and Microciona fasci- 

 spiculi/era Carter(3), — in which the spiculation consists of verti- 

 cally directed long smooth tylostyli, trichodragmata and, in 

 addition, acanthostyli. But this evidence is by no means con- 

 clusiAe, since the type of skeleton possessed by Dragmatyle is 

 common to quite a number of encrusting genera of very diverse 

 origin, — including, for example, (in addition to several genera 

 provided with acanthostyli), Timea and Halicnemia (s.str.) in 

 the Spirastrellida?, and Buharis in the Axinellida?. On the whole, 

 there is perhaps more to be said in favour of tlie inclusion of 

 Dragmatyle in the Axinellidie than can be advanced in the case 

 of Thrinacojihora. 



Genus Axidragma, gen.nov. 



Dejiiiitiou. — Axinellida? typically of thin lamellar habit, stijai- 

 tate, with even sui'face. Skeleton composed of primary lines of 

 stylote megascleres, traversing the sponge in the direction of its 

 growth, and of secondary lines (connecting fibres ?) formed of 



