Mr. H. J. Carter on TeichonellidEe. 39 



have just described ; but such is the case, and therefore I 

 have ventured, as a mere wanderer in this unknown field, at 

 least to me, to make the addition. No one can deny that the 

 illustrations of Haeckel's work are beautifully executed, and, 

 although rendered more attractive by being magnified and 

 accompanied by much diagram, still it would be ditficult to 

 place before the student any thing more impressive and useful. 

 But when we come to detail, this is distorted to suit the 

 theory: thus when we find the cilia of the "gastrula" or 

 embryo, which are the paddles by which it progresses, re- 

 versed, and the new being made to go with its nether or 

 obtuse end foremost in search of a place for fixation and 

 further growth, it will be only necessary to watch the embryo 

 under such circumstances, and its future development, to see 

 that the author of ' The History of Creation •* has been ima- 

 ginative. But, unfortunately, this does not rest here ; for then 

 comes the difficulty of knowing how far this imagination may 

 have extended (that is, how much may be true and how much 

 due to fancy) in the ' Kalkschwamme ;' 

 " Fronti nulla fides." 



As yet I only know of two species of Calcispongiee that 

 belong to the family Teichonellidas ; and they are remarkable 

 for their large size and peculiar mode of growth respectively. 

 Hitherto only sac-like forms have been recorded ; and these 

 find analogous ones among the siliceous sponges ; but now we 

 have analogous ones also to the muriform, proliferous, and 

 foliate siliceous sponges. It is not at all uncommon to find a 

 siliceous sponge assuming first the form of a fan, then that of 

 a clam-shell, with the vents on the concave surface, then 

 curving round still more until the opposite sides meet and, 

 lastly, uniting grow together so as to form a vase-shaped 

 sponge, which, but for the mouth being expanded instead of 

 contracted, would represent the sacciform shape of the calca- 

 reous sponges ; while the structure being the same, Teichonella 

 lahyrinthica would, with a contracted mouth, under the same 

 series of changes, become Grantia compressa. Probably 

 time will add more species to the family of Teichonellidte, each 

 of which may possess a different form from those mentioned. 



EXPLANATION OF PLATE II. 



Fig. 1. Teichonella proUfera^ n. sp., lateral view, natural size '. a a a, 

 largest lamina"; b b, proliferous lamin?e commencing; c, the 

 same, of greater dimensions ; d d d, vents and upper margin of 

 laminae ; e e, pedal points of attachment. 



Fiff. 2, The same, upper view, natural size, to show, a a a, margin of 

 lamina and vents. 



