124 



MOLLUSCA. 



No. 510. Ammonites Lyellii, Laymerie. 



This species is distantly allied to A. Rhotomagensis, Lamarck. From the 

 Gault, Dienville, France, and now in the private Geological Cabinet of Mr. Ward, 

 Rochester. Price, $0.30. 



No. 511. Ammonites macrocephalus, Schloth. 



This is the type of Von Bnch's group, " MacroceplicM " 

 which resemble the " Goronati" bnt are ordinarily more 

 inflated and have tubercles nearer the umbilicus. From 

 the Middle Oolite, Wiltshire, England, and now in the pri- 

 vate Geological Cabinet of Mr. Ward, Rochester. 



Diameter, 7. Price, $1.25. 



No. 512. Ammonites mammilatns, Schloth. 



From the Lower Cretaceous, of France, and now in the private Geological 

 Cabinet of Mr. Ward, Rochester. Price, $0.30. 



No. 513. Ammonites Mantelli. Sow. 



The Cretaceous Ammonites appear to 

 have had such tendency to variation, that 

 specific names have been needlessly mul- 

 tiplied, and thus this well-known Ammo- 

 nite has been described under several 

 synonyms. It belongs to the group, "Rho- 

 tomagenses." From the Lower Chalk, St. 

 Florentin, France, and now in the Ward 

 Museum, University of Rochester. 



Price, $0.75. 



No. 514. Ammonites . 



This is the inner cast of a gigantic species much resembling the A. Mantelli 

 in its markings, but much compressed laterally. Diameter, 31. Price, $6.00. 



No. 515. Ammonites margaritatus, Mumfort. 



Synonym of A. amaltheus, Schloth., and type of 

 group, "Amaltliei," of Von Buch, or Ammonites with 

 cordate keels. This is an exceedingly variable species. 

 From the Middle Lias, Charmouth, England, and now 

 in the private Geological Cabinet of Mr. Ward, Roch- 

 ester. Diameter, 7. Price, $0.75_ 



No. 516. Ammonites margaritatus Mum. 



This is a young shell from the same locality and Cabinet as the preceding. 



Price, $0.30. 



