A Month on the Trondhjem. Fiord. 441 



LXIII. — A Month on the Trondhjem Fiord. By the Rev. 

 Canon NoEMAN, M.A., D.C.L., F.R.S., &c. 



[Continued from p. 367.] 

 [Plate XIX.] 



BRACHIOPODA. 



1. 2'erehratulina caput-serpentis, Linu. 

 Trondhjem. 



Var. septentrional is, Couthouy. 



RoclLerg, on the precipices. I have always re- 

 garded, and must still regard, this as only a variety 

 of T. capiit-serpentts, notwifhstanding tlie opposite 

 opinion held by G. O. Sars *, Davidson f, and 

 Fischer and CEhlert \. Sars thought he had found 

 a permanent difference in the structure of the loop ; 

 but that has been proved not to be the case ; the 

 later authors rely on trifling differences, and I 

 cainiot find anything, either by the comparison of 

 the hundreds of specimens which have passed 

 through my hands or in the descriptions given, 

 on which to found a valid species ; the more speci- 

 mens are examined the weaker is the evidence of 

 real distinction, and T. capitt-serpentis, war. germanaj 

 F. & OS., is a mere link in a chain. Davidson 

 quotes in the memoir referred to, without apparently 

 the least suspicion that anytiiing was wrong, these 

 words from Binney's edition of Gould's ' Report 

 Invert. J^lassachusetts ' : — "The downy epidermis 

 is a character too rare and too singular to be over- 

 looked. This, however, is rubbed off very easily." 

 In his description of the species also Gould had 

 written : — " Tiie whole [/. e. shell] covered by a 

 thin, silvery, fibrous epidermis ; " and, again, 

 " Deshayes conjectures, probably with justice, that 



*■ G. 0. Sars, ' ^lollusca rog. avct. Norwe<,n,'C,' 1878, p. 10. 



t Davidson, *' Mon. liccent Jtaicliiopoda," Trans. Linn. !Soc. ser. 2, 

 vol. iv. (188(J), p. 28. 



I FLscher and (l'>hlcrt, Expud. Sci . ' Travailleur ' at ' Talisman,' Bra- 

 chiopodcrt, 1S9I, p. 2p ; and ilesult des Campajr- -Sci. I'riuco Monaco, 

 fasc. iii., J^mchiopodos dc lAtlan. Nord, 1892, p. 0. 



