EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 225 



in Albany county, N. Y., a sponge of uncertain form, apparently subspheri- 

 cal in which the spicules are largely hexacts with smooth and echinate arms. 

 The latter are very like those Gaspe spicules with spirally arranged asperi- 

 ties and though the Helderberg specimens are for the most part highly 

 irregular in this arrangement yet such an one as Girty's figure 23, plate i, 

 indicates the development of the asperities in uncomplicated spiral lines. 

 Dr Girty has described this species, typical of his genus Lysactinella, as 

 L. g e b h a r d i. 



So far then as actual similarities in spicular morphology are involved, 

 the nearest allies in structure which we can now find to our Gaspe 

 hexactinellids are in the Helderbergian of New York. 



Receptaculites jonesi Billings 

 Receptaculites jonesi ]5illings. Palaeozoic Fossils. 1865. 1:389, fig. 365 



Description. The specimens of this species that have been as yet collected are small, 

 turbinate, or depres3ed conical bodies, f-rom one to two inches across, and from six lines 

 to one inch in hight. The broadest extremity, supposed to be the base, is usually circular, 

 sometimes ovate, gently concave, and with an obtusely rounded margin all round, the 

 thickness of which is from three to five lines. The smaller extremity, or the upper side, is 

 a depressed cone, with an apical angle of 110° to 130°, with an irregularly rounded truncated 

 apex. The grooves of the radial stolons, as shown in the cast of the interior of the 

 ectorhin, radiate straight outwards to the margin, and run upwards over the rounded edge. 

 There are here (on the peripheral edge) four or five grooves in a width of three lines. 

 The grooves of the cyclical stolons are closer together, there being about nine in the width 

 of three lines. From the margin to the apex both systems of grooves become more 

 crowded together, and, at the apex, the ectorhin appears to have been of a somewhat 

 pliable, coriaceous integument. At the apex there are indications, in all the specimens 

 which have this part preserved, of a small irregularly rounded aperture, which is usually 

 depressed, in form, somewhat like the umbilicus of an apple. 



Several specimens have been collected which show the internal cavity. It varies 

 slightly in form in different individuals, but is, in general, bell-shaped. 



None of the specimens yet seen have the ectorhin preserved, and the form of the 

 plates is not, therefore, yet known. Dedicated to (the eminent English naturalist) T. 

 Rupert Jones. 



Locality and formation. Cape Gaspe, in the upper part of the Lower Helderberg 

 group, in beds holding a mixture of Upper Silurian and Devonian fossils. 



Collector. Prof. R. Bell. 



We have not seen this species. 



