284 



NEW YORK STATE MUSEUM 



Rhipidomella musculosa Hall var. Solaris nov. 



These are all small shells with the enormous adductor scar in a 

 state of high development. The shells are somewhat less circular. 



Rhipidomella musculosa var. Solaris 



more transverse than in the New York and Grande Greve Oris- 

 kany specimens of R. musculosa, but their specific identity 

 is not greatly veiled. 



Lower Devonic. Moosehead lake, Baker Brook point ; Brassua 

 lake, east side ; Moose river at Stony brook, Me. 



Schizophoria ? amii nov. 



Shell of medium size, transversely subelliptical in outline. Ven- 

 tral valve with slightly prominent beak which is not depressed 

 but from the umbonal region departs a low median sinus which 

 widens posteriorly and covers one third the width of the valve at 

 the anterior margin. The dorsal valve is the more convex specially 



III, .^'^ s. 



Schizophoria ? amii 



in the median region which is elevated into a broad ridge corre- 

 sponding to the concavity of the ventral. From this central ridge 

 the sides slope somewhat abruptly and with a slight depression post- 

 laterally. The surface is marked by fine angular radii very like those 

 of Dalmanella lucia Billings (sp.) and are rapidly increased 

 by implantation. Sometimes these striae are seen to end abruptly in 

 elongate punctae as in some species of Rhipidomella (R. p e n e 1 - 



