286 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxjcv. 



Beyrichia nodulosa expansa U'. lind- Beyrichia spin itlosa Boll. 



stronii, var expansa Kiesow). Beyrichia steusloffl Krause. 



Beyrichia noetlingi Reuter. Beyrichia trilobata (Entomis trilobata 



Beyrichia noetlingi conjuncta Reuter. Krause). 



Beyrichia pi a gosa a Jones. Beyrichia tuberculata (Bait us tuber- 



Beyrichia plicata (Entomis plicata culatus Kloeden). 



Krause). Beyrichia tuberculata bigibbosa Reu- 



Beyrichia pustulosa Hall. ter. 



Beyrichia reticulata (Strepula relicu- Beyrichia tuberculata foliosa Jones. 



lata (limbata in text) Krause). Beyrichia tuberculata spicata .Tones. 



Beyrichia rcuteri Krause. Beyrichia tuberculato-kochiana Reuter. 



Beyrichia salteriana Jones. Beyrichia umbonata (Beyrichia bol- 



Beyrichia scanensis Kolmodin. liana umbonata Reuter). 



Beyrichia (Steusloffia) simplex {Strep- Beyrichia tcaldronensis, a new species.'' 



ula simplex Krause). 



DEVONIAN SPECIES. 



Beyrichia aurita Riehter. Beyrichia, new species (B. Tclwdeni 



Beyrichia devonica Jones and Wood- var. Jones), 



ward. 



Approximately 225 named species and varieties, varying in time 

 from the Cambrian to the Permian, have, in the past sixty years, been 

 referred to Beyrichia. Of the total number, only the seventy-three 

 species and varieties listed above may be accepted as conforming 

 strictly to the genus as here characterized. Only a few of these are 

 Ordovician, and only two or three Devonian. The Cambrian species 

 are regarded as widely different and probably not Ostracoda at all, 

 while none of the Carboniferous species is strictly referable to the 

 genus. As restricted, then, Beyrichia is preeminently a Silurian 

 genus. 



It is interesting to note further that only four of these species are 

 as yet known in American deposits, and of these but one, Beyrichia 

 granulosa Hall, is found in the Ohioan province, the other three oc- 

 curring in the Atlantic and Polar provinces. All tin 1 remaining true 

 Beyrichia' seem to be confined to Baltic and British deposits, none of 

 (lie central and southern European species being, so far as known, 

 strictly referable to the genus. The list will be increased by two or 

 three as yet unpublished east American Silurian species, but even 

 with these (lie American representation is so weak that it is justifiable 



" American species. 



6 Related to B. moodeyi and />. maccoyiana, hut has a much broader marginal 

 border, a rather longer median lobe, and a distinctly reticulate surface which is 

 especially marked on the lobes. Tlie species presents considerable resemblance 

 to Beyrichia reticulata as figured by Krause, but differs in wanting the crest- 

 like ridge. See Plate XXXVII, tigs. 9, 10. 



Formation ami locality. — Niagaran (Waldron shale), Waldron, Indiana. 



Cotypes.— Cat. No. 41GU0, U.S.N.M. 



