•yU T\i\\: sK()(;si;i;n(; 



(about tlu> same as ii\ t\\v inali- ul A. ntrtd) aiul lia\f im inoxiiiial s|iinfs. The twc nr llircc 

 (lostorior daws an- aiimilatinl. 



'I'hi' lateral <■ y o s are buiuewhal lai'i^or lliaii tlmsc ol llir li'iiialc 



Matrnal. Remarks: — This species was iiitiiKlucfd iritu ilic litiiatuiv li\ <i. (). Saks, I8()!t. \k :i57. 



AltliDUjih tlie original description is vcrv dt'licieiit and is not ilhistruted by any ligures, it has, 

 all the same, seemeil ])ossible to succeeding writers who have dealt with these questions to 

 identify it. Even U. \V. Mfl.l.HH includes it, 1912. p. 45 as identifiable. This author writes 

 about this species (1. c): ,,l)er A. ainjssicola sehr iihnlich, weiiig gestreckter. 3. Thoraxbein 

 mit U> Borsten. Furca mit 5 Dornen, denen nnch •! Borsten folgen. GroBe o iind 9 1,34 mm." 



The comparatively small niinilicr of cleaning bristles on the seventh liiiili and of daws 

 ou the furca and the small length of the shell made me begin to suspect that G. O. Sahs had 

 based his description on a specimen that was not yet mature. This suspicion seeined, however, 

 to be directly contradicted by the fact that G. S. Brad^ and A. M. NORMAN, who, to judge 

 from the figures of the shell that they add, had mature specimens to investigate — ,, specimens 

 for which we are indebted to Professor Sars" — gave the same length of shell in their work of 

 1896 as G. (). Sars had given and merely quote Sars's description for other characters. On the 

 other hand this suspicion was confirmed still more strongly by a statement of G. 0. Sai^S himself, 

 as this author writes, 1887, p. 31 (203): ,,Naervaercnde Art" (-^ A. ublumja, length $ 1,7 mm., J 

 2,07 mm.) ,,upnaar saaledes gjennemgaaende en betydeligere Starrelse end foregaaende, skJ0ndt 

 den i denne Henseende staar adskilligt tilbage for den nordiske Art A. norvegica."'* 



In order to decide this point I wrote to Professor SARS asking if it was possible to re- 

 investigate the type specimen of this species. In reply to this (|uesti()n Prof. Sars communicated 

 to me that unfortunately it was quite certain tha-t this specimen was lost, but he sent me at the 

 same time two specimens, a mature female and a mature male, which he had determined as 

 specimens of A. norvegica. I could not of course decide with absolute certainty whether this 

 identification of Prof. Sars's was correct; as, however, the original description does not seem 

 directly to contradict it, I have accepted it. 



The result of the investigation of these specimens is given in the re-description of the 

 species given above. As is seen best from a comparison between Sars's original description 

 and my new description, it fully confirmed my suspicion that the type specimen had not 

 been mature. 



It does not seem impossible, however, that the specimens investigated by me are the 

 same as were previously investigated by G. S. Brady and A. M. NOR.MAN, on which they based 

 their information in their work of 1896. In this case it is a good illustration of these investigators' 

 methods of work. 

 The species captured As Will be Seen from a remark imder A. aherrata I had sent me a specimen caught in 



"'' "llela^ "' Strangford Lough, Irdand, which was defined by Prof. G. S. Bhady as A. Mariae (W. Baird) 

 and which after a carefid investigation proved to be a male in the penultitiiate larval stage, 



*,, The present species thus always allaiiis a consitii-i'ably j;reater size Uiaii I In- iJicrcilingoiic, allhiMigliiisilirnonsioiis 

 are considerably smaller than the Scandinavian species A. norvegica." 



