Siv Species of Shells. 349 



Margarita minutissima. 



j\r. testa minutissimii, globoso-subovatu ; anfractibus tribus, convexis, 

 longitudinaliter sulcatis ; spird brevi, obtusii ; sutum valclc impressa ; aper- 

 tuid orbiculari ; umbilico magno et profundo. 



Plate XVI. Fig 5. 



Shell very minute, subdiscoidal, globular-ovate, of a dull 

 ash-color ; whorls three, convex, with distinct longitudinal, 

 approximate sulci, running obliquely, and disappearing as they 

 approach the umbilical region ; spire very low and obtuse at 

 the apex ; suture deep ; aperture circular ; lip sharp and 

 nearly continuous posteriorly : umbilicus large and profound. 



Length about -}^-, inch, breadth about equal to the length. 



Habitat. Casco Bay. 



Remarks. I have never found but a single specimen of 

 this shell, which I took from the stomach of a haddock. It is 

 not very nearly allied to any of the other species found on 

 the coast. Under a magnifier, it somewhat resembles M. vari- 

 cosa, Nob. in the ultimate whorl. It is, however, readily dis- 

 tinguished by its very depressed and obtuse spire. 



Delphinula? coarctata. 



D. testa parva, subdiscoidea, imperforata ; anfractibus tribus, convexis, lon- 

 gitudinaliter minutissimc striatis ; ultimo anfractu maximo ; sutura cana- 

 liculata ; apertura intcgcrrima, circulari, intus flaviduJa. 



Plate XVI. Fig. 6. 



Shell small, subdiscoidal, much depressed, imperforate ; 

 whorls three, convex, minutely striated longitudinally ; last 

 whorl very large, composing a large proportion of the entire 

 shell ; spire much depressed and obtuse ; suture very deep, 

 being canaliculate above the body whorl ; aperture uninter- 

 rupted, circular, of a wax color within ; epidermis yellowish. 



Length I inch, breadth I inch. 



Habitat. Casco Bay. 



Remarks. I have hesitated much in characterizing this 

 shell. In examining the contents of fishes' stomachs, I have 

 frequently found specimens of it, but regarding them as mere 

 accidental varieties of some of our species of Litton'na, I 



