Prof. W, King oti Spirifer cuspidatus. 15 



M^Coy, in his description of the genus Spirifer ^ having in- 

 vested the perforated or " receiving valve with an internal 

 pseudo-deltidium "* (an expression not very clear), it is some- 

 what uncertain that such is the correct view. 



Professor de Koninck was the next to discover the process, 

 having in 1859 described it as occuning in Spirifer distansj 

 Sower by t J a species closely allied to Sp. cuspidatus, I have 

 succeeded in exposing a section of it, represented in fig. 10, 

 as disclosed in a specimen collected by myself some years ago, 

 near Derrybrian, about twenty miles south-east of Galway, 

 where it characterizes the Lower Carboniferous shales. The 

 process corresponds with that represented by De Koninck, and 

 more fully illustrated in Davidson's precited communication, 

 in having a projecting canal or ^^ incomplete tube'''' along the 

 median line of the back of the " transverse septum." 



I must now dwell more particularly on the last-mentioned 

 feature. Prof. Winchell described it, in 1863 1, as occurring 

 in an American form which I consider to be identical with 

 Spirifer cuspidatus^ also in Sp. granulifer. Whether he was 

 the first to detect the transverse septum may be considered 

 uncertain, seeing that Deshayes and M^Coy have noticed some- 

 thing Avhich may be the same ; but this appears certain : he 

 was the first to determine the existence of the ^* incomplete 

 tube." Winchell, believing the shell (the first one above 

 alluded to) to be an undescribed species, and generically dif- 

 ferentiated from all others in being furnished with a peculiar 

 apophysary system, was induced to regard it as the type of a 

 new genus : hence his name SyringotJiyris typa. 



In 1865 Mr. Meek extended the discoveries of Prof. Winchell 

 by finding the appendage in other American shells allied to 

 Sp. cuspidatus J also in specimens of this species from Millicent. 



Prof. James Hall has observed it in some others. In his 

 fourth volume of the ^ Palaeontology of New York,' lately 

 published, he mentions that Spirifer altus has the septum but 

 not the tube, and that in Sp. textus both parts occur asso- 

 ciated as in Sp. cuspidatus^. 



The discoveries by Dr. Carpenter, already mentioned, are 

 the latest that have appeared in connexion with the subject. 



I may now proceed to give an account of my own investi- 

 gations. 



* Brit. Pal. Foss. p. 191. 



t Mem. de la Soc. Roy. des Sc. de Li^ge, 1859. 



X Proc. Acad. Nat. Sc. Philadelphia, January 1863. 



§ I have derived this information from extracts, taken from Professor 

 J. Hall's new volume, in Mr. Davidson's recent article in the ' Geological 

 Magazine,' July 1867. 



