94 BULLETIN OF THE 



DEROCERATIDiE. 



Deroceras. 

 Deroceras minatum Hyatt. 



Loc. Plateau de Larzac ; Coll. Dr. Krantz. 



Abdomen depressed. Sides flattened or inclining toward umbilicus. 

 Septal lobes and cells very simple, with but few minor lobes. Abdominal 

 lobe broad and shallow. Superior lateral the same, and of nearly the 

 same size. Inferior lateral pointed and very small. Superior lateral and 

 interior lateral cells equally divided by minor lobes. Young are smooth for 

 the first two or three whorls. Tubercles usually make their appearance on 

 the third whorl and on the fourth ; these spread out into pilae, and other 

 untuberculated pilae arise between them. The pilaj are often slightly de- 

 pressed or concave along the siphonal line. 



Deroceras subarmatum Hyatt. 



Aram, subarmatus Sow., Min. Conch., v. 4, p. 146, pi. 407. 



Amm. subarmatus Young and Bird, Geol. York., p. 250, pi. 13, fig. 3. 



Loc. Milhaud (Dep. de l'Aveyron) ; Coll. M. Boucault. 



Deroceras acanthopsis Hyatt. 



A mm. acanthopsis D'Orb., Prod. Pal. Stratigraph., p. 247. 

 Loc. Villebois (Dep. Ain) ; Coll. Prof. Bronn. 



DACTYLOID^3. 

 Coeloceras. 

 Coeloceras Grenouillouxii Hyatt. 



Amm. Grenouillouxii D'Orb., Terr. Jurass., Ceph., pi. 96. 

 Loc. Fontaine Etoupe and Fours in Calvados, Plateau de Larzac, Che- 

 ville in Sarthe, and Semur ; Coll. Dr. Krantz, L. de Koninck, and M. Bou- 

 cault. 



Coeloceras Desplacei Hyatt. 



Amm. Desplacei D'Orb., Terr. Jurass., Ceph., p. 334, pi. 107. 

 Loc. Avallon (Dep. Yonne) ; Coll. M. Boucault. 



Coeloceras crassum Hyatt. 



Amm. crassw Phil., Cool. York., p. 12, fig. 15. 



Amm. crassus Quens'dt, Der Jura, p. 251, pi. 36, fig. 1. 



Amm. raquinianus D'Orb., Terr. Jurass., p. 332, pi. 106. 



Loc. Whitby, Milhaud, Laumiere, Cheville in Sarthe, St. Cyr bei Lyon. 

 Plateau de Larzac, Villebois (Dep. de l'Ain), Salins (Dep. Jura), Semur, 

 Montpellier, St. Quentin, and Pres de Verpillier ; Coll. L. de Koninck, Dr. 

 Krantz, L. Aga^iz, Prof. Broiu:, and M. Boucault. 



