7f) ^Ir. II. J. Carter on the Spotu/es 



out of the circular hole in the oyster-shell, and thus, opening 

 flower-like to the water, disclosed at the same time those 

 beautiful feather-like ap]icndages of the circumference, together 

 with the minute ]iores of the centre, for inhalation. 



The form of the vents, too, if anything, when fully exjianded, 

 tended to a trumpet-shaped opening; but the margin of all the 

 orilices, both inhalant and excurrent, was minutely serrated by 

 the ]irojectiou of the pointed ends of sjncules tied or webbed 

 togetlier by ti-ansparent sarcode, in which the denser parts, 

 hanging about the throwm-aside sjnculcs of the bundle, pro- 

 duced the feather-like forms mentioned. Thus the ap})arent 

 fringe was not in separate portions, as figured of OscuUna^ 

 but in the midst of the transparent sarcode. 



The largest of the papilliform inhalant area; did not exceed 

 the l-12tli of an inch in diameter ; and they were all more or 

 less difierent in shape, varying from a circle to an elongated 

 ellipse. "When fully expanded, the diameter of the head or 

 inhalant area was always greater than that of the cylindrical 

 body as it issued from the circular hole of the oyster-shell, 

 and, although funnel-shaped at the commencement, became 

 nearly flat when fully expanded. The body, too, was often 

 inclined or bent to one side, so as to give a drooping position 

 to the head, which, in the elongated elliptical forms, closed by 

 approximation of the sides, and in the round ones by contrac- 

 tion towards the centre. 



Although, when somewhat contracted and funnel-shaped, 

 the inhalant area presented the appearance of an osculum, on 

 no occasion were the two seen in the same papilla, as in 

 Schmidt's illustration, nor was there seen any transformation 

 of the inhalant into the excretory papilla, nor vice versa, as 

 might be anticipated from a knowledge of the internal struc- 

 ture connected with these systems in sponges generally. The 

 oscula and inhalant areas respectively and invariably continued 

 the same. 



When first examined, the papillfc had all withdrawn them- 

 selves within the margin of the holes in the oyster-shell, but, 

 after rest, began gradually to issue, first in a conical fonn, 

 when they a])peared to be covered with minute black holes, 

 which were the then bare ends of the pin-like spicules bris- 

 tling in a radiating direction all over the sm-facc of the cone. 

 As, however, the sarcode ascended the spicules (and, so to 

 speak, hung itself out upon them, probably for the |)urpose of 

 aeration) the whole top fell asunder into the fimbriated form 

 mentioned ; while the reverse rpiickly took place if, imder 

 this state, the papilla^ were touched with the point of a needle, 

 proving the sensibility of sponges to a mechanical stimulus. 



