116 A MONOGRAPH Q THE 



of D. ramosa. In a small specimen of this species which 

 I received from the Eev. A. M. Norman, who obtained it 

 at Jersey, the tension spicula were exceedingly numerous, 

 and were frequently grouped together in considerable 

 numbers, in the form of large, irregular, flat fasciculi. The 

 specimen was dredged off Jersey. It was attached to a 

 dead shell of Venus verrucosa. It did not exceed an inch 

 in height, but in other respects it closely resembled the 

 specimen from Eowey. 



10. Dictyocylindrus stuposus, Boioerbanl-. 



Spongia stuposa, var. damicoenis, Montagu. 

 kigida, Montagu. 



HaLICHOSDKIA CEKVICURN1S, Johnston. 



kigida, Johnston. 



Sponge. Arborescent, pedicelled ; branches slender, round, 

 or compressed, dividing dichotomously and trichoto- 

 mously ; covered with long, scattered spicula projecting 

 at right angles to the axis. Oscula and pores incon- 

 spicuous. Dermal membrane abundantly spiculous ; 

 spicula attenuato-sphero-stellate, radii acute, numerous. 

 Skeleton : spicula of the axis cylindrical, rather short, 

 and stout ; radial spicula attenuato-acuate, large and 

 long. Tension spicula acuate and acerate, long and 

 slender, very numerous, frequently fasciculated. 



Colour. Light to dark brown, when dried. 

 Habitat. Torbay, Mrs. Griffiths; Orkneys, Mr. 

 M'Andrew. 



Examined. In the dried state. 



The specimen presented to me by Mrs. Griffiths, of 

 Torquay, labelled Hal. stuposa, is exceedingly like the figure 

 represented by Montagu, ' Wern. Mem.,' vol. ii, pi. iv, p. 79, 

 in every respect. It differs essentially in its structure from 

 the type specimen of Halichondria cervicornis of Dr. 

 Johnston, figured in pi. v, fig. 1, p. 90, of his ' Hist. Brit. 



