144 



MOLLUSCA. 



No. 657. Radiculites (Sphcerulites) Hceninghausii/ besm. 



From the Lower Chalk, Dordogne, France, and now in the Ward Museum, 



Price, $0.75. 



University of Rochester. 



No. 658. Radiolites (Sphcerulites) crateriformis, D'Orb. 



Lower valve, From the Lower Chalk, Royan, France, and now in the Ward 

 Museum, University of Rochester. . Size, 6x6. Price, $1.50. 



No. 659. Radiolites (Sphcerulites) crateriformis, DOrb. 



Lower valve. This specimen shows the 

 peculiar form of growth which this shell un- 

 dergoes, the whole organism being much 

 modified — from the normal bivalve construc- 

 tion — by its sessile character and its perma- 

 nent attachment to the rock on which its sta- 

 tion was chosen in an early period of its devel- 

 opement. This lower valve shows the several 

 lines of its foliaceous growth, as also the " bi- 

 rostre," or internal mould, still filling the cen- 

 tral cavity. From the same locality and Mu- 

 seum as the preceding. Size, 6x6. Price, $1.50. 



No. 660. Sphserulites Bournoni, Desm. 



Both valves, with longitudinal section. From the Lower Chalk. Dordogne, 

 France. Size, 10 x 6. Price, $2.25. 



No. 661. Sphserulites calceoloides, Desm. 



Both valves ; the upper one showing its very peculiar projecting hinge-pro- 

 cesses. From the same locality as the preceding 



Size, 11 x 6. Price, $2.00. 



No. 662. Caprina adversa, D'Orb. 



This specimen of this most singular genus has both valves present, one of 

 them very large, elongate and sinistrally coiled, the other so short and stunted 

 as to resemble more the over-grown operculum of some Gasteropod shell. From 

 the Lower Chalk of Charente, France. Size, 9x7. Price, $2.25. 



No. 663. Caprina adversa, D'Orb. 



Another equally perfect specimen of the above, but with the lower valve 

 wanting. From the same locality as the preceding, and now in the Ward Mu- 

 seum of the University of Rochester. Size, 8x6. Price, $1.75. 



No. 664. AviCUla flabella, Conrad, 



This and the five following belong to the Aviculida or " Wing-shells," a 

 family characterized by a very oblique, unequivalved shell with a large posterior 

 muscular impression, long, straight hinge-line, and eared umbones. From the 

 Hamilton group (Devonian), Onondaga Co., N. Y. Price. $0.30. 



