Waller — Kinderhook Faunal Studies. 195 



is seen to possess a low, broad columella and the septa are 

 almost obsolete, being represented by faint ridges near the 

 sides of the cups. 



MOL.LUSCOIDEA. 



BRACHIOPODA. 

 Orthothetes inflatus (W. & YV.). 



PL XIX. f. 10-12. 



Original description. " Shell above a medium size, some- 

 what semicircular in outline ; the hinge usually a little shorter 

 than the greatest width of the shell causing a slight rounding 

 of the cardinal extremities. Pedicle valve concave in the 

 center, and elevated at the beak, which is straight and 

 pointed, directed obliquely backward from the hinge-line, 

 area rather high, irregular in width, and about one-third as 

 high as long ; delthyrium very narrow, extending to near the 

 point of the beak, closed to near the base by a thin, rounded 

 deltidium. Brachial valve strongly inflated, very prominent 

 on the umbo, a little flattened at the cardinal extremities. 



" Surface marked by moderately strong, rounded, somewhat 

 alternate, radiating striae, which present a wiry appearance. 

 The interior of the brachial valve is characterized by a very 

 large, flabelliform cardinal process, marked by several strong 

 plications." 



The dimensions of the type specimen are: length 28 mm., 

 breadth 28 mm., and thickness of the two valves 18 mm. 



Remarks, The type specimens of this species are from 

 both the magnesian limestone bed and the subjacent oolite 

 bed. The only specimen which is approximately perfect is 

 from the magnesian limestone and is here illustrated. 



Orthothetes inaequalis (Hall). ? 



PL VIII. f. 9. 



Among the specimens of Orthothetes from the magnesian lime- 

 stone bed at Burlington, there are two forms. The less com- 

 mon one is that already described as O. inflatus, in which the 

 length and breadth are approximately equal. The most abun- 

 dant form, however, is one having the breadth considerably 



