Morphology of the Blastoidea. 299 



field, being also pierced through the centre in its whole 

 length by a very fine canal, which led Mr. Rofe to suppose 

 that it was composed of two pieces." 



Two pages further on Mr. Ham bach proceeds " to the 

 description of the softer parts or organs which were protected 

 by the calcareous shell, though both are so intimately con- 

 nected with each other that one could not exist without the 

 other. If we examine these parts, which, in some cases, are 

 very beautifully preserved, we shall see that they are placed 

 below or above each other * ; and if we commence with that 

 portion which is placed immediately under the lancet piece of 

 the ambulacral field (see Plate a. Fig. 9a|)> we will here find 

 a longitudinal duct or vessel resting in the concave furrow of 

 the lancet piece, and running from the apex of the ambulacral 

 field to the summit, where it connects with a circular duct 

 (oesophageal ring?) surrounding on the interior side, the central 

 orifice or annulus centralis. This I have been so fortunate as 

 to obtain entire from a well-preserved specimen of Pentre- 

 mites Norwoodi; though, being probably composed of a very 

 fine and delicate tissue or membrane, it is destroyed in most 

 cases, and therefore very rarely observed." 



In the endeavour to summarize these statements J I wrote 

 as follows : — " Dr. Hambach, on the other hand, figures a 

 section of a ray (of Granatocrinus Norwoodi?), the lancet 

 piece of which is not only ' pierced through the centre in its 

 whole length by a very fine canal,' but also has a posterior 

 (sic) side which is ' concave, semilunar, and grooved in its 

 whole length for the reception of some duct or vessel.' At 

 the summit this duct or vessel ' connects with a circular duct 

 (oesophageal ring?), surrounding on the interior side the cen- 

 tral orifice or annulus centralis.' Thanks to the kindness of 

 Mr. Wachsmuth, I have been enabled to examine many 

 beautiful internal casts of Granatocrinus Norwoodi, a well- 

 preserved specimen of which is the original of Dr. Hambach'a 

 description ; but, despite this advantage, I am at a loss to 

 understand his meaning, and can only hope for a further ex- 

 planation of it in his forthcoming monograph." 



Here is Mr. Hambach's version § of this passage : — " Mr. 

 Carpenter says on p. 419 of his paper, I had figured and 

 described a section of a ray of Granatocrinus Norwoodi, but, 

 in spite of all advantages for examining beautiful specimens, 

 even the original which served for my description [|, he is at a loss 

 to understand the meaning. If Mr. Carpenter will go to the 



* I do not express " great doubts as to the correctness " of this statement. 



t In the explanation of tig. 9 we read : (a) fork piece. 



X 'Annals,' ser. 5, vol. viii. p. 4l!>. 



§ Trans. St. Louis Acad. vol. iv. p. 537. || The italics are«mine, 



