1863.] DR. J. S. BOWERBANK ON THE SPONGILLID.E. 461 



cylindrical, very short and stout. Ovaria, form unknown, furnished 

 with numerous scutulate spicula. 



Colour, in the dried state, light ash-grey. 



Hab. River Winguay, near Salto Grande, South America {W. 

 Bragge, Esq.). 



Examined in the dried state. 



This interesting species was brought from the interior of South 

 America by Mr. W. Bragge, who presented it to the Museum of the 

 Royal College of Surgeons. In a letter to Prof. Quekett he states 

 that it was " from the River Winguay, a branch of the Penk, from 

 near Salto Grande, above Paysandu ; it had a mass of red sandstone 

 for its base when found." Salto Grande is on the River Japura, 

 lat. 0° 28' S., Ion. 72° 37' W. This river is discharged into the 

 Amazon near Alvarens. 



The Sponge is 9 inches high, 7 inches broad, and varies from 2 to 

 3 inches in thickness. It has a nearly square outline ; and, in the 

 dried state, both in rigidity and general appearance it very closely 

 simulates a mass of finely branched coral. It is composed of a series 

 of anastomosing branches, two or three lines in diameter, forming 

 together a thick, somewhat fan-shaped mass. The surface of the 

 branches is smooth and even, or slightly undulating ; and they fre- 

 quently assume an oval form from the influence of the opposite linear 

 series of oscula, which are usually from two to three lines distant 

 from each other. 



The oscula rarely exceed half a line in diameter, and have usually 

 a slightly thickened and elevated margin. I could not detect pores 

 in the few pieces of dermal membrane that I found remaining on the 

 Sponge ; and both the dermal and interstitial membranes are thin and 

 very delicate in texture. The skeletou-spicula are curved, and are 

 remarkably short and stout : an average-sized adult one measured, 

 length -pty- inch, greatest diameter -^^ inch ; so that they are less 

 than six times their own diameter in length. Among the large cy- 

 lindrical spicula there were a few comparatively slender acerate ones ; 

 the dimensions of one of them was, length ^J-^ inch, diameter -tuVu 

 inch. These spicula, although differing in form from the adultske- 

 leton-ones, are only an early stage of their development, and they 

 may be traced through all stages of their growth, from the acutely 

 acerate to the hemispherically terminated adult spicula. The young 

 as well as the old spicula are remarkably solid, and it is only by the 

 aid of incineration that a very small central cavity can be detected in 

 them. In one of the small pieces of the Sponge, mounted in Canada 

 balsam, I found a fragment of an ovarium imbedded amidst the 

 spicula of the skeleton. In this fragment the foramen was well pre- 

 served ; and immediately around this orifice were numerous minute 

 mammillae at nearly equal distances from each other. A few of these 

 elevations exhibited a tolerably distinct circular line around them, 

 indicating, in a manner that admitted of little doubt, that they were 

 scutulate spicula, very similar in size and structure to those of the 

 ovaria of S. Brownii and S. Batesii, with the spicula of which spe- 

 cies they appeared to coincide as nearly as possible in size. No other 



