212 Mr. O. Thomas on 



Dall, from near Bird Island, in tlie mid-Pacific, and C. pafa- 

 gonica, Dall, from the coast of Chile and the Straits of 

 Magellan. It was at first suspected that in view of the 

 several species o£ brachiopods reported as common to the 

 west coast of North America and Japan, C. cahfornica and 

 C japonica might prove to be somewhat near akin, whereas 

 in fact they seem to belong to different subgenera, or even 

 genera. Mr. Hirase's specimens of the latter species were 

 taken at Hirado, Province of Hizen, Japan. 



The nomenclature pertaining to the rather complex topo- 

 graphy of the interior of the valves in tiiis group of brachiopods 

 does not appear to be in very satisfactory condition in the 

 literature, nor to be any too well correlated with that for the 

 remainder of the animal's anatomy. BL-ing in no position at 

 the moment to initiate a serious attempt at a remedy, I have 

 in this paper simply taken matters as I found them, and 

 endeavoured to make the be.st of it. 



Unfortunately some details, such as the central nipple-like 

 prominence, are not brought out very plainly in the figures. 



EXPLANATION OF PLATE XI. 



Fig. 1. Crania calif ornica, sp. n. Exterior of dorsal valve, X 3. 



Fig, 2. Ditto. Interior of dorsal valve, with the dried animal in situ, 



X3. 

 Fig. 3. Ditto. Interior of dorsal valve, after removal of the animal, X 3. 



The figures are from photographs by Bert on W. Crandall. 



XXI. — The " Huron " of the Argentine. 

 By Oldfield Thom.vs. 



(Published by permission of the Trustees of the British Museum.) 



While working out the San Juan huron, Grisonella, re- 

 ferred to in a succeeding paper, I have come to tlie conclusion 

 that my reference of the common huron of the Argentine to 

 the Brazilian Grisonella fnrax cannot be sustained. Wiien 

 making it, material of the Argentine form was much less 

 abundant than now, while, especially, I then su|)posed that a 

 specimen in the Museum, no. 44. 3. 7. 6, labelled ** Brazil, 

 purchased of Clausen,'^ was of too doubtful authenticity to 

 be taken as of any value. But I now know that this speci- 

 men was one of a series collected in Minas Geraes (probably 



