NO. 13 DIKELOCEPHALUS AND OTHER GENERA 357 



The Franconia formation. — In Wisconsin and Minnesota beneath 

 the strata referred to the St. Lawrence series are found more or less 

 calcareous shales and sandstones. The only trace of the Dikelo- 

 cephalinse is in the upper arenaceous shales and thin layers of sand- 

 stone of the Franconia horizon. This is found in Conokephalina 

 misa (Hall). The associated fauna is quite distinct from that of the 

 St. Lawrence formation, and includes (79a, 79b, 80a, 97, 99a, 100) : 



Obolus matinalis (Hall) Synirophia primordialis argia Walcott 



Oboliis mickwitzi Walcott Palaacmcea irvingi Whitfield 



Obolus (Westonia) aurora (Hall) Eccyliomphalus n. sp. 



Lingulclla mosia (Hall) Agnostus josepha Hall 



Lingiilella mosia osceola (Walcott) Agnostus parilis Hall 



Lingulella oweni (Walcott) Lonchoccphalus hamulus Owen 



Lingulella phaon (Walcott) Lonchocephalus wisconsinensis Owen 



Lingulella similis (Walcott) Ptychaspis granulosa (Owen) 



Lingulella winona (Hall) Ptychaspis miniscaensis (Owen) 



Lingulella winona convexa (Walcott) Ptychaspis striata Whitfield 



Lingulella (Lingnlepis) acuminata Chariocephalus ivhitfieldi Hall 



(Conrad) Chariocephalus sp. 



Dicellomus politus (Hall) Conaspis^ anatina (Hall) 



Eoorthis f diablo Walcott Conaspis bipunctata (Shumard) 



Eoorthis remnicha (N. H. Winchell) Conaspis eryon (Hall) 

 Eoorthis remnicha sulcata (Walcott) ■ Conaspis nasuta (Hall) 



Eoorthis remnicha winHeldensis Conaspis oweni {^HaW) ? 



(Walcott) Conaspis patersoni (Hall) 



Eoorthis sp. Conaspis perseus (Hall) 



Otusia sandbergi N. H. Winchell Conaspis ? shumardi (Hall ?) 



Billingsella coloradocnsis (Shumard) Ptychoparia diademata (Hall) 



Finkelnburgia finkelnburgi (Walcott) EUiptocephalus ? curtus (Whitfield) 



Finkelnburgia osceola (Walcott) Conokephalina misa (Hall) 

 Syntrophia primordialis (Whitfield) 



^ Conaspis Hall.* 



Dr. Th. Lorenz ^ places two species under the genus Macrotoxus: Anomocare 

 angelini Gronwall [1902] and Conocephalites perseus Hall [1863]. I think 

 A. angelini Gronwell is a true Anomocare and should be retained in that genus, 

 which makes Macrotoxus a synonym of Conaspis Hall. 



The genotype of Conaspis will now be C. perseus (Hall). It is representa- 

 tive of a group of species in the Upper Cambrian formations allied to Ptycho- 

 paria that are characterized by a subconical glabella, medium sized eye-lobes, 

 rather strong postero-lateral limbs, narrow fixed checks, and with facial 

 sutures extending almost directly forward from the eye lobes so as to form a 

 narrow frontal limb ; the frontal rim is usually well defined and cut obliquely 

 by the facial sutures. 



The species I now refer to Conaspis from the St. Croixan of the upper 

 Mississippi Valley are ; 



* Sixteenth Ann. Rept. New York State Cat. Nat. Hist., 1863, p. 152. 

 ^Zeitschr. deutsch. geol. Gesellsch., Bd. 58. 1906, p. 61. 



