TRENTON CONGLOMERATE OF RYSEDORPH HILL 77 



bulbous posterior part, strong sulcus and granulosa surface. Its 

 posterior bulb suggests species of Ctenobolbina, but as also 

 other Eurycliilinas have a email node just posteriorly of the 

 eulcus, it is evident that this bulb only represents an extravagant 

 development of such node. The degree of its convexity and its 

 granulose surface are features in which it is comparable to E. 

 g r a n s a , and E. subaequalis Ulrich, but these latter 

 do not possess the upturned marginal border, nor the strong 

 development of the posterior node. 



Eurychilina (?) solida sp. nov. 

 PI. .5, fig. 18 

 A single specimen of a granulose Eurychilina found in the com- 

 pact ostracode limestone of Kysedorph hill, agrees in most char- 

 acters with the preceding species but differs in others. These 

 are the perfect separation of the sulcus from' the cardinal line, 

 the sulcus forming here a small deep crescent-shaped pit near 

 the middle of the valve; the remainder of the carapace, except 

 the marginal area, is strong'-ly and very uniformly convex; and 

 the marginal area more strongly concave, and rising much higher 

 than in E. b u 1 b i f e r a . A break just behind the sulcus seems 

 to indicate the presence of a node. The exterior and interior 

 closing walls of the marginal area have not been observed, and 

 it is, therefore, not certain whether this form is really a Eury- 

 chilina, or i>ossesses only a simple border or ^' frill." 



Dimensions. Length 1.2 mm; hight .9 mm; thickness .3 mm. 



Horizon and locality. Compact gray limestone pebbles of the 

 Rysedorph hill conglomerate. (Group 6) 



Eurychilina subradiata Ulrich var. rensselaerica var. nov. 



Eurychilina subradiata Ulrich. Geol. 'Minn. Pal. 

 1897. V. 3, pt 2, p. 663 



PI. 5, fig. 4-7, 13 



Diagnosis. Oarapace rather large, elongate, semi-elliptic to 



subtrapezoidal, cardinal line longer than any other part of the 



shell, straight, cardinal angles short; anterior and posterior 



