NO. 5 CAMBRIAN TRILOBITES RESSER J 



Middle Cambrian, Pleasant Hill; (loc. lO/d) i mile northwest of 

 Henrietta, Pennsylvania. 



Cotypcs. — U.S.N.M. nos. 61579, 61580. 



Alokistocare pomona 



Alokistocare pomona Walcott, Smithsonian Misc. Coll., vol. 64, no. 3, p. 186, 

 pi. 25, fig. 6, 1916. 



It is not altogether certain that this species can remain in Alokis- 

 tocare because of the narrow cranidium, but without additional speci- 

 mens it cannot be determined how much of this is due to distortion of 

 the soft shale matrix. 



Middle Cambrian, Park: (loc. i59f) Near Sixteen, Montana. 



Holotype.—V.S.'^M. no. 61577. 



Alokistocare majus (Walcott) 



Acrocephalites ? majus Walcott, Smithsonian Misc. Coll., vol. 64, no. 3, p. 180, 

 pi. 26, fig. I, 1916. 



It appears that the median boss has been compressed laterally into 

 a ridge. 



Middle Cambrian, Meagher; (loc. 4g) North of Gallatin River, 

 east of Logan, Montana. 



Holotype.—U.S.'NM. no. 61578. 



Alokistocare piochense (Walcott) 



Ptychoparia pioclicnsis Walcott (part), U. S. Geol. Surv. Bull. 30, p. 2or, 

 pi. 26, 2b; pi. 28, figs. I, I a, b, e, 1886. (Not pi. 26, 2a, nor pi. 28, ic, 

 id = A. packi: pi. 26, fig. 2= Glyphaspis nezadensis.) 



Ptychoparia piochensis Pack (part), Journ. Geol., vol. 14, p. 297, pi. 2, fig. 4a 

 (only), 1906: (For other figures see below.) 



Liostracus piochensis Lorenz, Zeitschr. deutsch. Geol. Gesell., vol. 58, no. i, 

 p. 61, fig., 1906. 



Amecephahis piocliensis Walcott, Smithsonian Misc. Coll., vol. 75, no. 2, p. 53, 

 pi. 9, 1924. 



Amecephahis piochensis Walcott, idem, vol. 75, no. 3, p. 65, pi. 15, figs. 8-10, 

 1925. 



As originally set up this species was a mixture of specific and 

 generic forms. As used by Walcott in 1886, plate 26, figure 2a, and 

 plate 28, figures ic and id, represent another species, A. packi; plate 

 26, figure 2, represents Glyphaspis, which may be the same as that de- 

 scribed by Pack under the name Ptychoparia kenipi. Of Pack's fig- 

 ures, only 4a can possibly belong to Alokistocare ; however, if this 

 figure is correctly drawn, it is not piochensis, but an undescribed 

 species. Figure 4 appears to be A. packi, ^b belongs to Glossopleura 

 packi, and 4c to Clavaspidella howelli. 



