1863.] DR. J. S. BOWERBANK ON THE SPONGILLID^. 447 



sent to me ; and as I am not aware that the species has been de- 

 scribed and published before, I beg to dedicate it to my friend Dr. 

 J. Leidy, who has worked so well and worthily for the advancement 

 of science, and to whom I am indebted for my knowledge of the 

 species. 



Spongilla Capewelli, Bowerbank. 



Sponge massive, sessile ; surface uneven, often lobular, smooth. 

 Oscula simple, minute, dispersed. Pores inconspicuous. Dermal 

 membrane pellucid, aspiculous. Skeleton-spicula acerate, rather 

 short and stout. Ovaria subglobose ; spicula birotulate, rather long, 

 disposed in lines radiating from the centre of the ovary ; rotulae flat, 

 margins slightly and irregularly crenulate ; shafts slender, incipiently 

 spinous, varying in length from one to one and half diameter of a 

 rotula. 



Colour dull green, with a tint of yellow. 



Hab. Lake Hindmarsh, Victoria, Australia ; lat. 35° 30' S., long. 

 141° 40' E. (i. P. Capewell, Esq.). 



Examined in the dried state. 



We are indebted to the energy and enterprise of Mr. Capewell for 

 the knowledge of the existence of Spongilla in the freshwater lakes 

 of Australia. The specimen, the type of the above description, is 

 7^ inches long and 3 inches in its greatest diameter, surrounding in 

 a very irregular manner a small twig of wood, not \ of an inch in 

 diameter, and from which it projects in large tuberiform masses. 

 Mr. Capewell states in his letter to me that " the manner in which 

 it is found is, lying upon the shores. In the winter season, about 

 June, the weather being very tempestuous, the lake becomes greatly 

 agitated, and the roll and swell is so great that at times a small boat 

 could scarcely live upon the surface. It is after one of these storms 

 that, by searching along the shores, you may obtain specimens. I 

 have searched well for it among the reeds and upon the branches of 

 trees pendant in the water, but did not succeed in finding them in 

 those situations, and my impression has always been that it coated 

 dead branches of trees that have fallen some depth in the water. 



" The colour and appearance of the specimens when found is 

 exactly the same as the dried specimen would have if dipped in 

 water." 



The description of the habit of this Spongilla would do equally 

 well for that of our British species S.Jluviatilis, with which it assi- 

 milates in anatomical structure in a very remarkable manner. 



The oscula appear to be less in size, but more numerous, than in 

 the British species, and the skeleton less fragile. The skeleton-spi- 

 cula are shorter and stouter than those of S.Jluviatilis, their length 

 being in comparison about as 3 to 4. The ovaria are numerous ; they 

 are situated on the basal membrane in a single, closely packed stra- 

 tum, and do not appear dispersed in the substance of the deeply 

 seated portions of the sponge as in S.Jluviatilis. In their size and 

 general appearance they very closely resemble those of the British 

 species. Externally they are supplied with numerous short, curved. 



