Vol. 62.] TKILOBITES FROM BOLIVIA. 425 



16. Teilobites from Bolivia, collected by Dr. J. W. Evans in 



1901-1902. By Philip Lake, M.A.,F.G.S. (Read April 25th, 



1906.) 



[Plate XL.] 



The trilobites brought home by Dr. Evans are comparatively few 

 in number, but nevertheless they form a valuable addition to our 

 limited knowledge of the Lower Palaeozoic faunas of South America. 

 Several horizons are represented, and it is worthy of remark that, 

 while the earlier forms show affinities with the contemporaneous 

 European fauna, the Devonian species are much more closely allied 

 to those of South Africa and North America. This observation is 

 borne out by an examination of the trilobites described by Prof. 

 E. Kayser from Argentina, 1 by Dr. A. Ulrich from Bolivia, 2 and by 

 Dr. J. M. Clarke from Brazil. 3 



The following forms have been identified : — 



Peltura sp. \ Dalmanites Paituna, Hartt & 



Symphysurus Apolonista, sp. nov. j Ratbbun (?). 



Trinucleus boliviensis, sp. nov. j Dalmanites Maecurua, J. M. Clarke (?). 



Ogygia sp. j Dalmanites sp. 



Phacops cf. arbuteus, Lake. 



The specimens were obtained from the following localities 4 : — 



(1) Cochaiya, about 3 miles north-east of Pata, on the track 

 from Apolo to Pelechuco via Pata, Province of Caupolican, 

 Republic of Bolivia. 



Peltura sp. 



Two specimens of Peltura were obtained in soft, pale-violet or 

 purple shales in this locality. The beds clearly belong to the Upper 

 Cambrian, and are probably on the horizon of the Dolgelly Beds or 

 Upper Lingula-Fl&gs. 



(2) Large blocks of sandstone (not in situ) about a mile from 

 Apolo, Province of Caupolican, in a direction a little west of 

 north. 



Sympliysurus Apolonista, sp. nov. and Trinucleus boliviensis, sp. nov. 



1 ' Ueber primordiale & unt.ersilurische Fossilien aus der Argentiniscben 

 Eepublik ' Palaeontographica, Suppl. iii, Lief. 2 (1876) pp. 5 et seqq. See also 

 ' Beitrage zur Kenntniss einiger palaozoischen Faunen Siid-Amerikas ' Zeitschr. 

 Deutsch. Geol. Gesellsch. vol. xlix (1897) pp. 274-317 & pis. vii-xii ; and 

 I. Thomas, ' Neue Beitrage zur Kenntniss der devoniscben Fauna Argentiniens ' 

 ibid. vol. lvii (1905) pp. 233-90 & pis. xi-xiv. 



2 ' Palaozoiscbe Versteinerungen aus Bolivien ' Neues Jabrb. Beilage-Band 

 viii (1893) pp. 5-114 & pis. i-v. 



3 ' As Trilobitas do Grez de Erere e Maecuru, Estado do Para, Brazil ' Eev. 

 Mus. Nac. Eio de Janeiro, vol. i, 1895 [1895 on title-page ; 1896 on coloured 

 wrapper]. Published separately in 1890. 



4 Most of the places referred to here will be found in the map accompanying 

 Dr. Evans's paper on bis 'Expedition to Caupolican, Bolivia, 1901-1902' 

 Geogr. Journ. vol. xxii (1903) pp. 601-42. 



