73 



distance along its centre, and the spaces between the rays are 

 slightly undulating. 



Actinoptychus areolattis, Ehrb. 



A, sple7idens (Ehrb.), Grun., var. Halionyx, Grun. Several va- 

 rieties. 

 A. tindulattiSy Ehrb. 

 A, vulgaris, Schumann, var. Virginica, Grun. Several varieties. 



Amphitetras mimita, Grev. Rare. 

 Asterolanipra Marylandica^ Ehrb. Rare. 

 Azilacodiscus Crux, Ehrb. Two varieties. 

 Auliscus pruinosus, Bailey. 



A, spinosus, T» Christian. A. Schmidt (Atlas PL 125, fig. 2) 

 speaks of this as doubtfully an Auliscus, and Prof H. L. 

 Smith considers it rather more closely allied to GlyphodiscuSy 

 although he thinks the two genera might with propriety be 

 united. 



r 



Biddulphia aurita (Lyngb.), Breb. 



B. Bailey i, W. Sm. 



Biddulphia Brittoniana, Kain and Schultze, n. sp. 



A figure and description of this singular new form will be 

 given in a future paper. 



Biddulphia Cookiana, Kain and Schultze, n. sp. 



Valve orbicular-lanceolate; two processes at extremities of 

 longitudinal axis; three central spines; elevation at the centre 

 and apices slight; strise moniliform, radiate. (Plate LXXXIX. 



Fig. 4). 



We take pleasure in naming this beautiful form after Prof 

 G^o, H. Cook, State Geologist of New Jersey. 

 B. decipiens, Grun. Rare. 

 B, elegantula^ Grev. A careful study of the many varieties of 



this diatom found in the deposit, and a comparison of them 



with B. Tuomeyi, also found in it, make it seem probable that 



they are only varieties of the same species. 

 B, pulchella. Gray. Rare. 

 B. rhombus (Ehrb.), W. Sm. 

 B, setiatlosa, Grun. 

 B. Tuoineyi, Bailey. 

 B, ttirgida (Ehrb.), W. Sm. 



