C. E. BeeGher — N. A. Species of Strophalosia. 241 



Missouri. Besides - these three species, others from various 

 formations have been described and referred to different genera 

 which, it is believed, will eventually be included under Stroph- 

 alosia, and others thus determined may ultimately be placed 

 elsewhere. Several will require the reexamination of the type 

 specimens, and the study of additional material, before any 

 fixed conclusions can be reached, so that they will be but 

 briefly noticed in this place. 



Produclella truncata Hall,* from the Marcellus shale, uni- 

 formly shows a truncation or cicatrix of the ventral beak, indi- 

 cating an early condition of attachment which is very sugges- 

 tive of Strophalosia. This relationship was recognized by 

 Professor Hall in 1857 (loc. cit.), where he says in some 

 general remarks on the " Producti of the Hamilton and Che- 

 mung groups : " a Among these are several forms which ex- 

 ternally have the form of Strophalosia." J. F. Whiteaves, 

 F.G.S.,f recently again recognized these relations, and refers 

 to the species as Productella {Strophalosia?) truncata. He 

 also illustrates a specimen of Strophalosia productoides Mur- 

 chison, from the Devonian (Hamilton) rocks on the Athabasca 

 River, identified by Thomas Davidson, and this, so far as 

 known, is the first unqualified recognition of the genus in 

 ISTorth America. Chonetes muricatus Hall,:j: offers about the 

 same amount of evidence as Productella truncata, and may 

 tentatively be placed with Strophalosia. 



Dr. Shumard in 1858§ described a species from the Permian 

 of Texas as Aulosteges Guadalupensis, and in a subsequent 

 .paper in the same volume, he again refers to it as Strophalosia 

 {Aulosteges) Guadalupensis, giving two figures in illustration. 

 The writer is unable, either from the figures or description, to 

 express any definite opinion as to its generic relations, and 

 doubts whether it will go into either of the two genera men- 

 tioned. 



In 1864, Professor Winchell provisionally referred a species 

 to Strop halosia\ with the specific name of nummularis, which 

 apparently belongs to this genus or to Productus. In this 

 instance, again, further examination of specimens is requisite. 



The principal object of these citations is to call attention to 

 the species which have been referred to Strophalosia, and to 

 suggest others which may ultimately go with it. The two 



* Tenth Ann. Rept. N. T. State Cab. Nat. Hist., p. 151, 1857. 



f Contributions to Canadian Palaeontology, vol. i, pt. II, p. 112, 1889. 



± Pal. N. Y., vol. iv, p. 142, 1867. 



8 Transactions of the St. Louis Academy of Science, vol. i, p. 292, 1858. 



| Proc. Acad. Nat. Sci. Philadelphia, vol. xv, p. 4, 1864. 



