Geographical Distribution of the Terebratulae. 183 



Subgenus 9. Gwynia?, King. 



Apophysis unknown. 



40. Terebratula {Gwynia ?) capsula, Jeffreys, Ann. & Mag. Nat. 



Hist. 1859, iii. pi. 2. f. 7 a, 6 ; Conch. Icon. pi. 10. f. 39. 



Terebratula capsula, Jeffreys. 

 Gwynia capsula. King. 



Hah. Plymouth; iVorwan. Belfast Lough; flyndfmfln. Etretat, 

 Normandy; Jeffreys. 



Is this very minute form, it has been asked, an adult shell, or 

 the fry of Argiope cistelluhm or of some other Terebratula ? 

 An Argiope it certainly is not ; and I am unable, after a most 

 tedious examination of specimens, to add anything to what is 

 known on the subject. Its history is as follows : — In the ' Annals 

 and Magazine of Natural History ' for August 1858, Mr. Jeffreys 

 announced that a very minute brachiopodous shell (2Vth of an 

 inch in length and ^\jth, in breadth) had been found by Mr. 

 Norman (a well-known collector of British shells resident in 

 Durham) among some shell-sand received by him from Ply- 

 mouth. " Being so excessively small,^' adds Mr. Jeffreys, " as 

 to defy any attempt to examine the internal structure without 

 injuring the specimen, it is impossible to say whether it is an 

 Argiope; but having carefully compared it with. A. cistellula, 

 which varies greatly in form, I am inclined to consider it at pre- 

 sent an extreme variety of that species." Attention being 

 drawn to the subject, other specimens were dredged by Mr. 

 Hyndman in Belfast Lough (reported, however, to be Argiope 

 cistellula), and by Mr. Jeffreys himself at Etretat, on the coast 

 of Normandy. After an examination of specimens under a 

 magnifying power of 100 diameters, Mr. Jeffreys came to the 

 conclusion that the shell was not an Argiope, but a form more 

 allied to Terebratulina. Is it then the fry of T. caput-serpentis ? 

 Mr. Jeffreys thought not, because the valves are nearly equal, 

 and have no indication of the radiating dichotomous ridges of 

 that species. But what do we know of the Brachiopods in the 

 fry state ? Is it at all likely that they bear the detailed charac- 

 teristics of the adult ? He described it in the following year 

 (Ann. and Mag. Nat. Hist. January 1859) simply as a Tere- 

 bratula, with the remark, " it may be a question whether it 

 ought not to be placed in a new subgenus." Prof. King, of 

 Queen's College, Galway, upon seeing this announcement, lost 

 no time in borrowing the specimens, and, in compliment to Mr. 

 (J. Gwyn) Jeffreys, created the genus Gwynia for its reception 

 (Proc. Dubl. Univ. Zool. Assoc. April 1859). Prof. King says, 

 " The principal generic character of Gwynia is in the labial ap- 

 pendages being attached directly to the shell, and not to a loop." 



