NARRATIVE OF THE CRUISE. 447 



contact, partly by transverse connecting trabecular (synapticulse) between closely approxi- 

 mated parallel spicules ; so that the adhesive process commences at one portion of the 

 sponge, and is gradually continued to a greater or less extent. 



" The order Lyssacina may be divided into four families — (1) Euplectellidse, 

 (2) Asconematidae, (3) Hyalonematidas, (4) Rossellidse — which, apart from numerous other 

 characters, may be easily distinguished as follows by the radially or tangentially directed 

 spicules of the external membrane. 



" The Euplectellidse possess in the external membrane dagger-shaped six-rayed spicules 

 with an elongated proximal ray. 



" The Asconematidre have ' pinuli,' that is six- or five-rayed spicules, whose strongly 

 developed distal ray is in the form of a pine-tree, while the proximal ray is either 

 entirely wanting or only feebly developed ; ' amphidisks ' are entirely wanting in this 

 group. 



" The Hyakmematidas possess both pinuli and amphidisks. 



" The Rossellidse bear spicules in which the distal ray is either entirely wanting or 

 much reduced, while the proximal ray is either strongly developed or also wanting ; 



dp* 



Fig. 170.— Characteristic spicules of the Uncinataria. 

 a, " Unciuatum," b, "Clavnla" of Farrea haecke/li, n. sp. ; c, "Scopula" of Burete carter!, n. sp. 



indeed two rays belonging to the same tangential axis may both be wanting, so that only 

 simple tangentially directed rods remain. 



" The Dictyonina may be divided into two suborders, Uncinataria and Inermia. 

 The former are characterised by the possession of sharply pointed rods, ' uncinate,' 

 which are abundantly provided with proximally directed recurved hooks ; the latter are 

 devoid of such ' uncinata.' 



" In the first family of Uncinataria, the tubular or calyciforni Farreidse, there are 

 found in the external membrane radially disposed acicular rods, the ' clavulae,' while 

 the five remaining families, instead of such ' clavulae,' possess ' scopulse,' that is radially 

 directed structures formed like brooms or forks, with from two to eight prongs, the latter 

 are termed Scopularia, whilst the former are called Clavularia. 



" To the Scopularia belong — 



" 1. Euretidse, in the form of a branched anastomosing tubular structure, or of a goblet 

 with lateral outlets. 



" 2. Melittionidae, of goblet or tubular form, witn honeycomb-like walls. 



