228 Ann'als of the Carnegie Museum. 



This little brachiopod is very common at a number of localities 

 in the Champlain Valley. For a generic diagnosis it is necessary 

 to depend upon the external characters, as no specimens have as yet 

 been obtained which show the brachidia. Several specimens have 

 been examined for spirals by the transparency method, but without 

 success. However, the shape of the shell, with its deep dorsal sinus 

 and ventral fold remove it at once from the Rhynchonellidcc, and sug- 

 gest the ZygospirincE, as Whitfield has already pointed out. While 

 it seems probable that this shell is a Zygospira, its exact generic 

 reference must await more favorably preserved material. From the 

 stratigraphic position of the formation in which it is found, it may 

 be expected to show a somewhat simpler brachidium than Zygospira 

 niodesta, perhaps approaching the form found in Hallina. 



Description. 



Shell elongate, oval, widest near the front, pointed at the apex. 

 Pedicle valve convex, with a low fold on which are three plications. 

 Brachial valve "shorter than the opposite one, more nearly oval in 

 outline, with a deep narrow sinus which extends almost to the beak. 

 Surface marked by from thirteen to fifteen sharp plications on each 

 valve. Pedicle beak extended, sharp, not incurved. 



The young of Camarotcechia are very similar in appearance to these 

 specimens, but are somewhat broader and less deeply lobed. Z.? 

 aciUirostris has one large, very sharp plication in the center of the pedicle 

 valve. 



Locality. — Common in the Lower and Middle Chazy at Valcour 

 Island, Valcour, Chazy, and Crown Point, New York, and Isle La 

 Motte, Vermont. 



Order Neotremata Beecher. 

 Family SIPHOxXOTRETID^ Kutorga. 



Genus SciiiZAMBON Walcott. 

 12. Schizambon duplicimuratus Hudson. 



(Plate XXXIV, figures 23-25.) 

 Schizambon duplicimuratus Hudson, 1905. Report New York State Paleontolo- 

 gist for 1903, p. 284, PI. 5, figs. 6, 7. 



Shell nearly circular in outline, slightly unsymmetrical. Both valves 

 are moderately convex, the surface lamellose and covered with small 



