382 Mr. H. J. Carter on the " Tuhulations Sahleuses " 



to arrange themselves in so limited a space : it can be clearly 

 seen that the wings have tlirown themselves into a multiplicity 

 of closely packed transverse folds, representing increments of 

 growth in length, and that these, again, have disposed them- 

 selves, in gi'oups, in Avavy (longitudinal) folds representing 

 growth in breadth ; so that the wings, plaited and folded up in 

 this complex manner, present a superficial resemblance to the 

 surface of a much-convoluted brain or to a portion of a trans- 

 verse section of a Labyrinthodont tooth. 



This mode of development of the wings obtains in all Ortho- 

 pterous insects, upon larvae of which these observations are 

 mainly based — at least in some Neuroptera {Termes), and 

 probably universally in the groups which Westwood, years 

 ago, collectively termed the Homomorphic Insecta. 



XXXVII. — Note on the " Tuhulations Sahleuses " of the Etage 

 BruxelUen in the Environs of Brussels. By H. J. Cartek, 

 F.R.S. &c. 



[Plate XVin.] 



In the * Annales de la Society Malacologique de Belglque,' 

 t. ix. pi. iii. 1874, M. A. Rutot published an excellent paper 

 on the '^ Gr^s Fistuleux et Tuhulations Sahleuses de I'^tage 

 Bruxellien " in the environs of Brussels, chiefly dwelling 

 on the fossil sponge-spicules found about them ; and thus 

 attention has been directed to these interesting objects, which 

 otherwise might have remained in abeyance for an inde- 

 finite period. 



Knowing the interest which I have taken in the Spongida 

 both recent and fossil, my kind friend M. Ernest Vanden 

 Broeck, of Brussels, obtained from M. Rutot a copy of his 

 paper, and, together with some of the sand containing the 

 sponge-spicules, forwarded the same to me in April 1876, 

 following it (as I had expressed an opinion somewhat dififerent 

 from the conclusions to which M. Rutot had arrived) by a 

 box containing several specimens of the " tuhulations sa- 

 hleuses " themselves, for my examination. 



These specimens, which were preceded by a letter and 

 sketches from M. Vanden Broeck explanatory of the contents 

 of the box &c., reached me in August 1876 ; and having had 

 many engagements to fulfil since them, my examination of 

 them has necessarily been postponed to the present time (Feb. 

 1877). 



There are eighteen specimens of the '' tuhulations," with 



