Species of the Waverly Gropp. Ifil 



Type, Thamnodictya Newhen-yi, Hall. 



In the observations made upon the genus Hydnocekas, reasons liave been 

 given for discontinuing the generic term Dictyopiiyton. It is not necessary 

 to recount these further than to recall that the tenn was introduced, not 

 primarily to replace Conrad's name Hydnoceras, but as a designation for 

 other, and anodose species, the first among the specified types being 

 BicUjophjton Newherryi, the form subsecpiently adopted as the type of Tham- 

 nodictya. Dictyopiiyton has proved to be a misleading term among the 

 sponges, and its place is better filled by the various generic terms which the 

 recjuirements of our present knowledge have originated. 



Thamnodictya Newbeuuyi, Hall. 



Platk l, Figs. 1-6 ; Plate lii, Fia. 1. 



1863. Dictyophytmi Newberry i, Hall, Sixteenth Ann. Kept. N. Y. State Cab. 



Nat. Hist., p. 87, pi. iv, figs. 1, 2, 4, (not fig. 3). 

 1882. Phragiiwdictya Netoherryi, Hall. Notes on the Family DictyospongidsB ; 



Expl. pi. 17, figs. 10, 11. 

 1884. Thamnodictya Newherryi, Hall. Thirty-fifth Ann. Kept. N. Y. State 



Mus. Nat., Hist., p. 477 (partim) jjl. (17) 18, figs. 10, 11. 



Sponge of moderate size, attenuate and subcylindrical toward the base, 

 rapidly expanding above, forming a broad vase supported upon a long pedicel.' 

 Cross-section at any point of the vase circular ; the pedicel however ajjpears 

 to have been obscurely prismatic. 



Heticidum, composed of strong rectangularly intersecting bands, the 

 primary series being broad and forming trapezoidal quadrules, averaging, 

 over the main portion of the vase, about 6 mm. in diameter and 9 mm. in 

 height. The vertical strands diverge very rapidly outward with the growth 

 of the cup, losing their conspicuous size toward the aperture. The subordi- 

 nate net-work is sharp and fine, especially in the apertural region where the 

 prevalence of the finer strands obliterates the coarser meshes. The pedicel, 

 which is not well preserved in any of the specimens studied, appears to have 

 borne coarse vertical ridges toward its upper part. 



Dimensions. The original example of this species is the most complete 



in the collections examined. Its length from the lower end of the pedicel, 



which appears to be nearly complete, to the aperture, is 115 mm. ; the median 



width of the pedicel, 7 mm. ; the diameter of the aperture, 90 mm. Portions of 



2?^ 



