38 Observations on the Terrestrial 



once between the two species by comparing the following figures. 

 j \ Figure 89 is Pupilla badia from Port- 



land, Maine ; Figure 90 represents a 

 specimen of P. muscorum from Eu- 

 rope. P. muscorum having the same 

 number of whorls, is a much smaller 

 shell than P. badia, the labrum is also 

 Fig. 89. Fig. 90. thicker, and behind the labrum the 



thickening appears like a light colored band, which we do not 



observe in Pupilla badia. 



VERTIGININ^. 



Isthmia ovata, Say. 



Occurs under chips and stones in open fields, close by pools 

 of water ; have also found it in drier situations. More common 

 near the coast. 



^^^_^ Buccal plate, (Fig. 93J corneous, strongly arcuate, cutting 



' / / 1 l\J/^ edge projecting in the centre, sides square and parallel with 

 Fig. 93. a transverse line of the body. Plate wrinkled longitudinally. 



Lingual membrane 90-14-1-14, central plate large, square, with rounded 

 corners, furnished with three short denticles, and also on the posterior edge 

 two elevations ; laterals long and narrowing posteriorly, tridentate, inner denticle 

 slightly larger ; uncini broad and short, with four small denticles, or rather 

 notched. (PL 10, Fig. 94.J) 



Isthmia Gouldii, Binney. 



Found generally in company with smaller species of Pulmo- 

 nates. Body light bluish, blotched with black, tentacles black, 

 rather long, swelling at tip, a black line from tentacles extending 

 along the back. The shell is carried high on the back. In motion 

 they are exceedingly lively. 



Buccal plate, (Fig. 95,) slightly arcuate, rounded 

 Wy at sides, of the same lengtli throughout, longitudin- 

 ally lined, and transversely striated. 

 Fig. 95. Lingual membrane, 75-11-1-11, central plate 



square, notched at the outer posterior corners, having three small rounded den- 

 ticles, laterals square, bidentate, uncini minutely notched. {PL 10, Fig. 96.) 



