76 A MONOGRAPH OF THE 



Genus — Halyphysema, Bowerhank. 



1. Halyphysema Tumanowiczii, Bowerbank, 



2. — ramulosa, Bowerbank. 



1. Halyphysema Tumanowiczii,* Bowerbank. 



Sponge. Pyriform, pedicelled, base expanded, thick, 

 turgid at tbe margin; pedicel gradually enlarging 

 upwards, fistular, parietes very thin, surface smooth 

 and even ; distal extremity abundantly hispid. Oscula 

 and pores inconspicuous. Dermal membrane thin 

 and translucent. Skeleton. Membranous, with an 

 incorporation of fragments of spicula of various sizes 

 and forms, and of minute grains of sand. 



Colour. — Alive ; bluish white ; milk white when dried. 



Habitat. — Diamond Ground, off Hastings, Mr. Tumano- 

 wicz ; Berwick Bay, Dr. Johnston ; Cullercoats (?), Mr. 

 Alder. 



This species is remarkable as being the smallest known 

 British sponge. It rarely exceeds a line in height. It is 

 found based on the stems of small fuci and zoophytes, and 

 frequently in considerable numbers. It varies but little 

 from the normal form, but occasionally the pedicel is com- 

 paratively considerably elongated, and it is then often more 

 or less contorted. The distal end is usually pyriform, but 

 sometimes it is found nearly globular, and in one case it 

 was projected at nearly right angles to the axis of the 

 pedicel. When seated on a flat surface, the base of the 

 sponge has much the same form as half of an orange 



* Pronounced Tumanovitchii. 



