[Eixlooeras] duplex," Walilenherg et auctt, 395 



conical/' and the proportionate size of the siphuncle, " occu- 

 pying about a third part of the entire shell." These two 

 characters would obviously not be sufficient for specific dis- 

 tinction , and the vagueness of the original description has 

 given rise to a number of widely differing forms being placed 

 under one specific name, according to the interpretation, gene- 

 rally a very liberal one, that each author has put upon the 

 description. To make confusion worse confounded another of 

 Wahlenberg's species — ^^ Ort/ioceras commune'''' — has become 

 entangled in the nomenclature of "0. duplex.'''' According 

 to the original description of the former (JSTov. Act. he. cit. 

 p. 85) 0. commune is not an Endoceras, but an OrthoceraSj 

 for the siphuncle is described as of moderate thickness, 

 " equal to nearly a tenth part of the diameter of the wliole 

 shell, taken transversely," and " is for the most part situated 

 midway between the axis and the circumference of the shell." 

 Hisinger "^, who was the first to give figures of fossils under 

 Wahlenberg's names " duplex " and " commune,^'' adds very 

 little to our knowledge of those forms, and to his brief de- 

 scription of the former he appends the words " an species 

 distincta?" a somewJiat significant phrase, which seems to 

 suggest the difficulty he experienced in identifying Wahlen- 

 berg's species. 



Having thus failed in obtaining the required information 

 from the books, I explained vaj difficulties to Dr. Lindstrom, 

 and he, with no less kindness than promptitude, caused 

 inquiries to be made for me as to whether Wahlenberg's 

 types of "0. duplex'''' and "0. commune'''' still existed in the 

 museum at Upsala, where some of his types are preserved. 

 But they could not be found, so that there is now no possi- 

 bility of identifying Wahlenberg's species. Dr. Lindstrom 

 informed me, moreover, that he had " searched in vain '■* in 

 the "■ Hisinger Collection-" of the Royal Museum, Stockholm, 

 for the original specimens of "0. duplex " and "(9. commune " 

 figured by Hisinger in the ''Lethaja Svecica.' 



Under these circumstances it is desirable, as Dr. Lind- 

 strom has suggested to me, that Wahlenberg's names should 

 be relinquished, and new ones imposed upon all Swedish and 

 Russian Endocerata which have hitherto fallen under them. 

 This task has been already partly accomplished by such able 

 palaeontologists as Dewitz and Schroder in Germany and 

 Holm in Sweden, and, so far as I am aware, there remain 

 now very few forms requiring emendation. The collection of 

 Swedish specimens of Endoceras in the British Museum has 



* 'Lethfea Svecica,' 1837, p. 28. 



28* 



