l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 149 



Genus undetermined A 

 Plate 3, figures 13, 15, 16 



Discussion. — An interesting small, very wide shell is unique in the 

 collection from Hard Luck Creek. In outline and configuration of 

 anterior commissure it resembles the small shells that can be identified 

 as Xenambonites (pi. 2, figs. 21, 23, 25). However, it is much wider 

 at the hingeline and is costellate, unlike the Xenambonites species 

 described. Its affinities must remain uncertain until adult shells with 

 this ornamentation are secured. 



Figured specimen. — USNM 145353. 



Superfamily STROPHOMENACEA Schuchert, 1896 



Genus CHRISTIANIA Hall and Clarke, 1892 



Christiania sp. 



Plate 3, figure 21 



Discussion. — A single broken brachial valve assignable to Chris- 

 tiania is present in the silicified material from Hard Luck Creek. The 

 exterior is encrusted with siliceous foreign material, but the interior 

 shows two pairs of strong bladelike, divergent plates characteristic 

 of the genus. 



Figured specimen. — USNM 145355. 



Genus undetermined B 

 Plate 3, figures 11, 12 



Discussion. — A single fragment of a brachial valve exhibits the 

 hinge line, general shape, and brachial apparatus of a leptaenid. Al- 

 though no other specimens are available, this fragment is illustrated 

 to indicate a potentially important element of the brachiopod assem- 

 blage. It is hoped that more specimens will be present in the future 

 collections from eastern Alaska. 



Figured specimen. — USNM 145352. 



