93 
MODIOLA ? alzformis. 
TAB. CCLI. 
Spec. Cuar. Triangular, inflated ; back straight ; 
posterior lobe very small; anterior lobe flattish ; 
central part convex, elongated, with project- 
ing beaks. 
Leenern nearly twice the breadth ; the projecting part 
of the anterior side, which gives it a wing-like form, 
makes this shell approach to Avicula. The posterior 
lobe is somewhat acuminated : between it and the prin- 
cipal lobe is a concave space. The depth of the two 
valves united is equal to the width. The surface is 
rather rugged and imbricated. 
This was sent me from Sandgate, on the isle of 
Wight, by the Rev. W. D. Conybeare, who seemed to 
think it might possibly be a Hippopodium. It is how- 
ever sufficiently distinct from the type of that new genus 
figured in tab. 250. It somewhat resembles Avicula 
and Modiola, but I am at a loss to determine to what 
genus it really belongs, and there is not much chance 
of discovering the parts about the hinge. 
