XXVI 



MESODESMA. 

 Deauratum, 53. 

 Donacilla, 53. 

 M. ? Castaneum, 54. 



AMPHIDESMA. 



Prismatieum, 54. 

 Tenue, 55, /. 24. 

 Boysii, 55. 



CORBULA. 



Nucleus , 56. 



SPH^NIA. 



Binghami, 61, f. 32, 33. 

 Svvainsoiii, 57 (o). 

 Costulata, 245. 



PANDORA. 

 Obtusa, 57, /. 15. 

 Rostrata, 58. 



HIATELLA. 



Rugosa, 58. 

 Arctica, 59. 



AGIN A (p). 

 Purpurea, 60. 



FENERUPIS. 



Irus, 60. 

 Perforans, 6 1 . 



PETRICOLA. 



Ochroleuca 

 Fragilis, 62). 



PSAMMOBIA. 



Tellinella, 62. 

 Costulata, 62. 

 Laskeyi, 63. 

 Polygoua, 63. 

 Ferroensis, 64. 



SANGUINOLARIA, 



Rugosa, 64. 

 Vespertina, 65. 



TELLINA. 



Lineata, 65. 

 Punicea, 66. 



Not impossibly the young M ya Arenaria. 

 Scarcely differing from HIATELLA. 



