70 CATALOGUE OF THE BLASTOIDEA. 



observations terminate, and he proceeds to infer that these supposed tubes are the 

 external ends of a set of ovarian tubes which are situated " below the hydrospiric sac 

 and between the plicas." He gives us no information whatever as to how these tubes 

 pierced the hydrospiric sac on their way to the external opening ; while, as we shall 

 point out later on, his " ovarian tubes " are merely the restricted portions of the body- 

 cavity, which are enclosed between two adjacent lamellae of the hydrospire-apparatus. 

 Shumard's description may be insufficient and incorrect ; but if the material at 

 Hambach's command was perfect enough to enable him to speak in these terms of 

 the work of his distinguished predecessor, he might surely have devoted more than 

 five lines to a readable account of what he saw in a structure which had only been 

 found preserved in three specimens, two of them being in his own collection. 



Mr. Wachsmuth has sent us a fine specimen, which may perhaps throw some light 

 on this difficult question (PI. I. fig. 8). The peristome and spiracles are almost 

 completely covered by what seems to be the base of the little pyramid described by 

 Shumard. The upper part of this pyramid in the examples described by Shumard and 

 Hambach seems to us to be constituted by the proximal pinnules, as in the specimen 

 represented on PL V. fig. 28. In Mr. "Wachsmuth's example of P. sulcatus, however, 

 these proximal pinnules are not preserved, and the angles of the pyramid extend 

 outwards towards the pointed ends of the visible parts of the deltoids. At two of 

 these angles there seem to be indications of a double series of plates above the 

 spiracles ; while the structure is a little more irregular at two of the other angles, and 

 somewhat more so at the remaining one, which we take to be that of the anal side. 

 The central part of this covering is obscure, and we have been unable to make much 

 out of it ; but we have little doubt that this is fundamentally the same structure as 

 was seen by both Shumard and Hambach. According to the latter author, there are 

 " about five " of the supposed tubes to each spiracle ; while Shumard says that two 

 series of pieces stand over each opening, and except in the anal interradius this seems 

 to be the condition of Mr. Wachsmuth's specimen also. But we do not think that 

 the pieces have the tubular nature which Hambach assigns to them ; for we doubt 

 whether they are more than the proximal pinnules grouped round the peristome, as 

 shown in our PL V. fig. 28. Neither do we see any reason to suppose, as Hambach 

 does, that the tubes extend down into the interior of the calyx ; for they could hardly 

 do so without leaving some evidence of their passage through the central ends of the 

 deltoid plates, and nothing of the kind is visible in any of the numerous specimens of 

 Pentremites sulcatus which we have examined. 



We are much more inclined to think that we have here to deal with an extension 

 of the smaller system of summit-plates which occur in other Blastoids. In Granato- 

 crinus and Elceacrinus only the peristome appears to be covered (PL VII. figs. 4, II, 

 13 ; PL XVIII. fig. 1G), except perhaps for the anal plate in Granatocrinus Norwoodi ; 

 while Orqphocrinw and Stephanocrinus have a group of plates around the anal 



