278 ERNEST WARREN. 



In tlie absence of tlie gonosome,, however, the present 

 hydroid can only provisionally be referred to the genus 

 Eudendrium. The species is named angustum with 

 reference to the narrow or almost obliterated digestive cavity. 



(4) CI a vat ell a mnltitentaculata sj^.n. (PI. XL V, figs. 



7-9.) 



A small clump of this species was found embedded in a 

 white siliceous sponge at the edge of a small rock-pool full of 

 corallines, and situated at some distance above the low-tide 

 line (figs. 7 and 8). 



This delicate little hydroid, reaching a height of about 

 ^ inch, has a circle of numerous capitate tentacles, and the 

 hypostome is richly coloured. Around the mouth there is an 

 area of chalky white, below this there is a band of lemon 

 yellow, and just above the circle of tentacles an irregular 

 band of bright red. 



Trophosome. — The hydrorhiza consists of a thin tube, 

 which ramifies through the substance of the sponge. Diameter 

 about 0*13 mm.; the perisarc is yellow and fairly stout, being 

 about ll'Sfi. 



Hydrocaulus. — Upright stems springfromthe hydrorhiza 

 and grow through the sponge to the upper surface. In com- 

 parison with the size of the hydranth, the hydrocaulus is 

 slender, and it appears to be highly extensile. 



Foreign bodies, such as minute particles of sand and diatoms, 

 readily cling to the perisarc, and they may form a quite dis- 

 tinct coat. 



Diameter of embedded portion about O'lSmm., thickness of 

 perisarc 13"1 ^u; on emerging through the sponge the hydro- 

 caulus has a greater diameter, being about 0"ol mm., while 

 the perisarc becomes very thin and transparent, being about 

 4-4^ thick. 



Hydranth. — The polyp is relatively large (fig. 8), and 

 looked at from above it is star-shaped. The hypostome is 

 swollen and conical, with a small apical mouth {mo.), and is 



