]30 Annals of the Carnkcik Museum. 



line of the process and has its external opening in a pore just at the 

 joint where the chilidium meets the ajjex of the valve. 



Teetli. — In the pedicle valve, in front of the area, and separated 

 from it by grooves, are two strong crenulated teeth which fit into 

 sockets on either side of the platform of the cardinal process. These 

 teeth seem to have practically the same form and position in all stages, 

 but as they fit at such an angle in their sockets that it is almost impos- 

 sible to separate the valves without breaking them, it is only rarely 

 that a young specimen retains them. They have been seen in no 

 specimens less than two mm. in length. 



Septum. — In front of the bases of the crura there arises a rather 

 thick, low, septum, which, about midway of the shell, increases 

 abruptly in height till it reaches nearly to the opposite valve, then 

 falls off less rapidly and terminates at a point which is about one 

 fourth the length of the shell from the anterior margin. From the 

 point where it begins to rise it is thin and sharp. This sej^tum is 

 well developed in young stages. A specimen 2 mm. in length has a 

 septum exactly similar to that of the adult. 



Bracliiditim. — Only a part of the loop has been seen in the present 

 material. One adult specimen has two quite stout lamellce which ex- 

 tend upward and slightly inward and reach about half way to the 

 highest point of the septum. At their anterior ends they are flat- 

 tened and turned slightly outward. Near the posterior ends are what 

 appear to be the bases of processes which would have extended out- 

 ward and upward. Another specimen, 2 mm. in length, shows about 

 the same amount of the loop, but the two lamellae diverge at a 

 greater angle. 



PiDictce. — The shells are very highly punctate, especially toward 

 the front. From the point where the plications begin, up to a length 

 of about three mm., the punctce are confined ^ rincipally to the depres- 

 sions between the plications. There are two rows to each furrow. 

 From that point they are scattered abundantly all over the surface. 



The Same Fossil from OtJier Localities. 

 Calcified specimens from Ludlowville, Moscow, York, East Bethany 

 and Eighteen Mile Creek, N. Y., were taken for comparison with the 

 specimens in the present collection. Those from Ludlowville, York, 

 and Eighteen Mile Creek resemble closely in size, index, and form, 

 the specimens from Canandaigua Lake. Those from Moscow and 



