124 THE NAUTILUS. 



margin 10.5. Cotype (in Univ. Colo. Museum), broken specimen, 

 maj. lat. 20.5, min. lat. 17, alt. 14. Cotype (in possession of Mr 

 Bethel), with third whorl depressed, maj. lat. 20.5, min. lat. 17, alt. 

 in front of aperture 9.5. Cotype (in Acad. Nat. Sei. Phila.), maj. 

 lat. 21.2, min. lat. 18.2, alt. 13.1 mm. 



Type locality, Bright Angel Trail, Grand Canyon, Arizona. 



NOTES ON THE ANCYLIDAE OF NORTH AFRICA. 



BY BRYANT WALKER, SC. D. 



(Concluded from p. 



The following so-called species of the Ancylus fluviatilis group have 

 been listed from Algeria by Bourguignat and others: 



Ancylus brondeli Bgt. 



costulatus Kust. 



compressiusculus M. T. 

 subriparius Bgt. 

 epipedus Bgt. 

 ftitviatilis L. 

 bledahensis Bgt. ==fluviatilis gibbosus teste Westerl. 



djurdjurensis Deb. 

 peraudieri Bgt. 

 platylenus Bgt. 

 raymondi Bgt. 

 striatus Q. & G. 



simplex Fer. fluviatilis teste Clessin and Westerlund. 

 gibbosus Bgt. =fluviatilis var. teste Clessin and Wester- 

 lund. 



strictus Mor. 



In this connection it seems necessary to call attention to the per- 

 sistently erroneous use of Ancylastrurn Bgt. for this group by the 

 continental authors, e. g., Fischer, 1881, p. 504, Clessin, 1882, p. 

 27, Westerlund, 1885, p. 89, Germain, 1913, p. 261. 



As Hedley (1894, p. 118) has already shown, Bourguignat twice 

 gave A. cumingianus as the type of that group. " Since the de- 

 scriber of the group clearly and repeatedly declared his type to be 

 cumingianuSi it is not legitimate for Fischer, Clessin or Tryon to 

 alter the type of Ancylastrum from A. cumingicmus to A. ftuviatilis. 



