378 The Araerican Geologist. 



June, 1 



names of Battus nudus and B. integer. The discovery of an entire speci- 

 men by this author removed the doubts regarding the affinities of these 

 fossils with the order Trilobita. 



The investigations made by M'Coy in 1846, Syn. Silurian Fossils of 

 Ireland, p. 56, added the new genus TrinoduH and one new species, T. 

 agnostiformu. The non-adoption by palaeontologists of Tvinodus, and 

 the imperfect illustration of this species have caused several identical 

 forms to be classed under new names such as Agnostus convexus Salt. 

 A. trinodus Salt, and A. tardus Salt., Brit. Pal. Foss. 1851, p. 141 (not Bar- 

 rande's species). The species ranges high up in the geolog-c column as 

 it approaches its extinction, in the zone with the genus Asaphus and 

 Trinucleus. 



Barrande described in his Preliminary work on the Silurian System 

 of Bohemia, 1846, pp. 14 and 35, nine new species under this genus; 

 which he reduces to six in his final great work on the Bohemian trilo- 

 bites. Etage C with Parddoxides hoheiidciu contains — Agnostus integer 

 Beyr., A. granulatusBa.TT., A. nudus Beyr.^ A. hibuUutus Barr. and A. rex 

 Barr. Etage D with Asiq^ltus nob ills contains Agnostus tardus Barr. 



Corda, Prodrom 1847, reclassifies the genus into seven new genera and 

 29 species. All the genera and species have been referred to well 

 known Bohemian species and genera. 



In the Mem. Geol. survey, vol. 2, part 1, p. 351, pi. 8, Salter & Phillips 

 reproduce under the name of Agnostus trinodus the Irish species which 

 M'Coy described as Trinodus agnostiforuiis. The authors also describe a 

 variety of this species as connexus. 



1851 — Angelin describes and figures 12 species from Sweden, Pahieont. 

 Scand., p. 5, pi 6. Regie A (Olenus zone). Agnostus 'jnsiforrnis Linn^, 

 A. IcBvigatus Dalm., A. reticulatus Aug., Regio B (Paradox ides forchham- 

 meri zone), Agnostus planieauda Aug., A. exscu.lptus Aug., A. punctuosus 

 Ang., A. aculentus Ang.. A. hrenifrons Ang., A. glandiformis Ang., A. bituber- 

 culatus Aug., Regio C (Asaphus zi me), Agnostus lent if orru is Aug., Regio 

 D., Agnostus glabratus Ang. 



The first North American contribution to Agnostus was made by Bil- 

 lings in 1860, Canadian Nat., vol. 5, p. 302, in which he describes from 

 the so-called Quebec group, three new species, Agnostus americanus, A. ■ 

 orion and A. canadensis. These species are republished in Pa];i!Ozoic 

 Fossils of Canada, vol. 1,1865, p. 395. Agnostus (imericunus is of the type 

 Longifrontes, congeneric with A. trisectus Salt, which occurs at An- 

 drarum with Peltura and SpJucrophthalrnus. A. orion differs from A.pisi- 

 formis by having the glabella proportionally shorter. Tlie same name 

 was used by Barrande in 1846 for a species of the genus. 



1860 — Eichwald, Lethea Rossica, vol. 1, p. 1351, The author describes 

 four species, two of which are for the first time illustrated — Agnostus para- 

 doxus Eichw. and .4. nodiger, n. sp. Eichwald refers A. boeckii to A. 

 exseulptus Ang. The two new species are from the Asaphus zone. 



1863 — An important contribution to American paleontology was pub- 

 lished during this year by James Hall; entitled Preliminary notice of 

 the fauna of the Potsdam Sandstone, 16th Report N. Y. State Cab. Nat. 



