140 SUPPLEMENT TO THE 



specimens discovered having presented that character ; and I added " no calcareous 

 support for the labial appendages ; cardinal process much produced ; hinge-teeth large 

 and prominent." 



Mr. Whitfield vrrites me on the 22nd of March, 1881 : " Your Streptis Grayi is a 

 form you sent to Prof. Hall many years ago ; at that time he handed them to me ; I cut 

 two individuals and found spirals similar to those of Atrypa." This statement would 

 not, however, quite agree with what Prof. Hall wrote me at the time, and which will be 

 found alluded to in a footnote on p. 141 of my ' Silurian Monograph.' He said in his 

 letter that spirals had not been actually discovered but might ultimately be found, and 

 Prof. Hall has since assured me that none had ever come to his notice. Further, 

 experiments may determine the point at issue. 



Streptis Grayi is not a very rare shell and can be readily obtained by washings from 

 the Lower- Wenlock Shales at Buildwas in Shropshire. It occurs also in the Upper- 

 Silurian Rocks of Bohemia, and has been figured by Mr. Barrande in vol. v, pi. 83, 

 fig. 3, of his monumental work, ' Systeme Silurien du Centre de la Boheme,' 1879. 

 None of the Swedish specimens of the species I have been able to examine showed any 

 trace of spiral appendages. 



Genus — Eichwaldia, Billings, 1858. 



23. Eichwaldia Capewelli, i)«y. ' Sil. Mon., PL XXV, figs. 12—15; Sil. Sup., 



PI. VHI, figs. 15, 16. 



Rhynchonella reticularis? Hall. Trans. Alb. Inst., vol. iv, p. 21". Abstract, 



p. 23, May, 1863. 

 Eichwaldia — — 20th Report State Cabinet Nat. Hist., p. 275, 



1867. 28th Annual Report, pi. xxvi, figs. 

 50—54, 1875. 

 — Capewelli, Bav. Lindstrom ; Fragmenta Silurica, p. 25, pi. 2, 



fig. 16—20, 1880. 



At. p. 193 of my ' Silurian Monograph' I described the external characters of this 

 beautiful little shell, also some of its interior details. 



I have always felt uncertain whether this shell was provided with any calcified 

 supports for the labial appendages. In 1881 I placed in the hands of Mr. Glass 

 a number of well-preserved specimens obtained by Mr. G. Maw from his washings 

 of the Lower- Wenlock Shales of Buildwas, and after many trials Mr. Glass arrived at the 

 conclusion that it had none. 



Having received from Prof. Hall a number of well-preserved specimens of his 

 Eichoaldia reticulata from the Niagara groups at Waldron, Indiana, I found that they 



