2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



Lectotype. — U.S.N.M. no. 53410; paratypes, 110s. 53407, 53409, 

 53411,53412. 



Albertella bosworthi Walcott 



Albertella bosworthi Walcott (part), Smithsonian Misc. Coll., vol. 53, no. 2, 

 p. 22, pi. I, figs. 4, 5, 1908. (Not 6=: A. similaris; 7 := A. nitida). Idem, 

 vol. 67, no. 2, p. 38, pi. 7, figs. 3a, 3b, 1917. (Not 2-2h=zA. robsoncnsis; 

 3, 3c ^ A. similaris; 3d = .4. nitida.) 



Much confusion exists among the illustrated specimens assigned 

 to this species because the wide and narrow forms and those in which 

 there is a macropleural development of the fourth or the third thoracic 

 segment were not noted. 



Middle Cambrian, Ptarmigan; (iocs. 35c, i8a, 63m) Mount Bos- 

 worth, and (loc. 63 j) Popes Peak, above Ross Lake, British Columbia. 



Lectotype. — U.S.N.M. no. 53416; paratypes, nos. 53413, 63763; 

 plesiotypes, no. 85221. 



Albertella similaris, n. sp. 



Albertella boszu'orfhi Walcott (part), Smithsonian Misc. Coll., vol. 53, no. 2, 

 p. 22, pi. I, fig. 6; pi. 2, fig. 6, 1908; idem, vol. 67, no. 2, pi. 7, figs. 3, 3c, 

 1917 (see A. boszvorthi) . 



Albertella helena Walcott (part), idem, vol 53, no. 2, p. 19, pi. 2, fig. 6, 1908. 



This species is close to A. boszvorthi, differing chiefly in its longer 

 pleura, wider pygidium, and striated free cheeks. 



Occurrence same as preceding. 



Holotype. — U.S.N.M. no. 63762; paratypes, nos. 53414, 53415, 

 ■53417- 



Albertella rossensis, n. sp. 



Albertella helena Walcott (part), Smithsonian Misc. Coll., vol. 53, no. 2. 

 p. 19, pi. 2, fig. 7, 1908 (see A. helena). 



This species is similar to A. helena in shape and in the macropleural 

 development of the third segment, but differs in having coarser gran- 

 ules and in lacking both the axial spines on the pygidium and the 

 short interpleural furrows. 



Occurrence same as preceding. 



Holotype and paratypes. — U.S.N.M. no. 53403. 



Albertella nitida, n. sp. 



Albertella boszvorthi Walcott (part), Smithsonian Misc. Coll., vol. 53, no. 2, 



p. 22, pi. I, fig. 7, 1908. Idem, vol. 67, no. 2, p. 38, pi. 7, fig. 3d, 1917 



(see A. bosworthi). 

 Albertella helena Walcott (part), idem, pi. 2, figs. 8, 9, 1908; idem, vol. 67, 



no. 2, p. 39, pi. 7, figs. 5, 5a, 1917 (see A. helena). 



