302 MR.T. DAVIDSON ON JAPANESE BRACHIOPODA. [Apr. 18, 



septum is elevated as in Magasella. Indeed I am not quite satisfied 

 as to the genus Magas having been represented in the recent state, 

 although T. patagonica of Gould has been doubtfully referred 

 to it. 



Mr. Dall seems also inclined to separate Thecidium from the Tere- 

 bratulidce ; but I do not feel convinced that he has clearly shown that 

 Professors Suess, Deslongchamps, King, myself, and others have so 

 much erred in considering the excavated lobes or crescents in the 

 dorsal valve to be homologues of the loop. But that question may 

 require further examination ; and as no specimen of the genus has 

 been hitherto obtained from the Japanese waters, I will defer the 

 discussion to another occasion. 



Genus Terebratula, Llhwyd. 



But very few recent species have been discovered. Terebratula 

 vitrea, Born, T. minor, Philippi & Suess, T. sphceroidea, Phil., 

 T. uva, Brod., and T. cubensis, Pourtales, have been referred to it ; 

 but it is still a question whether T. cubensis and T. minor are more 

 than varieties of T. vitrea. A shell bearing great resemblance to the 

 fossil T. sphceroidea of Philippi was also dredged by Messrs. Jeffreys 

 and Kent near the coast of Portugal. Mr. Dall adds T. unguiculus 

 (Cooper) to the recent species of the genus Terebratula ; but I feel 

 satisfied that Cooper's species will be more correctly placed in the 

 genus or subgenus Terebratulina. From the Japanese waters we are 

 acquainted with but a single species. 



Terebratula minor, Philippi & Suess. (Plate XXX. figs. 10, 

 11, 12.) 



Terebratula vitrea, var. minor, Philippi, 1836. 



Terebratula affinis, Calcara, 1845. 



Terebratula davidsoni, A. Adams, Proc. Zool. Soc. p. 314, pi. 19. 

 fig. 30, 1867. 



This shell has been well described by Mr. Adams in the ' Pro- 

 ceedings of the Zoological Society.' Mr. Jeffreys, however, is of 

 opinion that the Japanese specimens cannot be distinguished from 

 the pliocene and recent specimens known under the designation of 

 T. minor or affinis ; and I must admit that Mr. Adams's two examples 

 bear a good deal of resemblance to the European shell. 



Hab. Dredged by Mr. A. Adams at Satanomosaki in 55 fathoms. 



Subgenus Terebratulina, D'Orb. 



I am inclined to consider this to be a subgenus of Terebratula, as 

 the characters of its loop so nearly approach to those of the last- 

 named genus. The number of recent species attributable to this 

 subgenus has been considerably exaggerated, and several of them are 

 no more than local variations or synonyms of the well-known and far 

 spread T. caput-serpentis ; T. japonica, T. septentrionalis, T. atl- 

 gusta, T. abyssicola, T. cancellata, T. eumingH, and one or two 

 more seem referable to the Linnean species. Mr. Dall believes T. 



