NO. 3 CAMBRIAN TRILOBITES 1 89 



Dr. James Hall (1863, pp. 147, 148) considers Lonchocephalus a 

 synonym of Conoccphalites, although realizing that to unite Crepi- 

 cephalus and Lonchocephalus with the typical form of Conoccpha- 

 lites is difficult (p. 148). 



To the general description of Owen we may now add that the 

 thorax has seven segments and that the dorsal shield is convex with 

 an elongate oval outline. The only entire specimen has a length of 

 4.25 mm. Surface of the type species unknown, as all specimens are 

 preserved as casts in a fine-grained sandstone. Specimens of L. minu- 

 tus, L. pholus, L. plena, and L. appalachia have a more or less granu- 

 lated surface with a shallow pitting in places. 



Genotype. — Lonchocephalus chippewaensis Owen. 



Stratigraphic range and geographic distribution. — Lonchocephalus 

 chippewaensis, L. minor, and L. sospita occur in the Upper Cambrian 

 Eau Claire formation, of Wisconsin and Minnesota ; L. bunus in the 

 Franconia formation, Minnesota ; L. minutus in the Potsdam sand- 

 stone, eastern New York ; L. appalachia in the Maryville limestone, 

 Alabama ; L. pholus and L. plena in the Weeks formation, western 

 Utah, all Upper Cambrian. 



Observations. — I think the species referred to Lonchocephalus 

 should be characterized as having a short convex glabella, short 

 frontal limb, and narrow frontal border, median spine on the occipi- 

 tal ring, six or seven thoracic segments, and a relatively large, well- 

 developed pygidium with continuous border and strong axial lobe. 

 As restricted, there are seven species now known to me : L. chippe- 

 waensis Owen, L. minor (Shumard), L. minutus (Bradley), L. bunus 

 Walcott, L. sospita Walcott, L. pholus Walcott, and L. plena Wal- 

 cott. The second species referred to Lonchocephalus by Owen, L. 

 hamulus, is placed under the new genus Saratogia. 



Of named and described genera Lonchocephalus is most nearly 

 related to Liostracus Angelin, 1854.'' With only the cranidia for 

 comparison, the difference between them is in the frontal limb and 

 rim, and the absence of well-defined glabellar furrows in Liostracus. 

 The typical species of the latter occurs in the Middle Cambrian 

 Paradoxides oelandicus zone of Sweden, and Lonchocephalus is an 

 Upper Cambrian genus as far as known in America. 



The specific name Lonchocephalus fecundus is mentioned by 

 Safiford in a list of fossils from the Knox shale,^ but the species 

 was not described or illustrated. 



^ Pal. Scand., p. 27. 



^ Geology Tennessee, 1869, p. 212. 



