16 Observations on the Terrestrial 



or striated. In Hyalina, the buccal plate is crescentic witli a 

 central projection, in this the plate is more like those species we 

 include under Valloninse. In short this genus is related to Hyalina 

 in the characters of the lingual dentition, and to Vallouinie in the 

 character of the shell and buccal plate. 



Pseudohyallna exigua, Stimpson, 



Occurring all over the State, and in favorable positions found 

 in abundance ; generally prefening low, wet ground, though 

 sometimes living in situations comparatively dry. 



The body is quite narrow and long, greenish Avhite, marked 

 with black along the back. The tentacles coarsely blotched with 

 black. The costse are more numerous on the shell of this species 

 than in P. asteriscus, and are also more solid and not so projecting; 

 they run moreover not parallel with the lines of accretion but 

 obliquely across them ; the surface of the shell is reticulated by 

 numerous longitudinal lines somewhat waved and nearly as prom- 

 inent as the costfe, which extend to the apex, which is thus 

 distinguished from the granulated apex of P. asteriscus. The 

 space between these longitudinal lines, is marked Avith minute 

 transverse rugfie extending from one line to the other, though 

 f requently.terrainating midway between them ; these run obliquely 

 across the costas and parallel with the line of aperture. The whole 

 surface of the shell presents a most beautiful appearance when 

 highly magnified. {Plate 2, Fig. 8.) 



Lingual membrane, 69-16-1-16, central plate long, having one long slender 

 denticle and two small ones ; laterals longer than wide, outer j^osterior angle 

 projecting, bidentate, larger denticle the length of plate ; uncini aculeate, those 

 nearest the laterals having a small denticle on their outer sides. {PL l,F'uj. 33.) 



Pseudohyalina minuscula, Binney. 

 A few specimens only have been found in the vicinity of 

 Portland. It would seem that this is its extreme eastern limit. 



C~~~~7jji]jjjljj|]jj|ii^ ~~) Buccal plate, (Fig. 34,} nearly straight, rounded 



■ — at ends, faintly striate longitudinally, slightly raised 



Fig. 34. in centre of cutting edge. 



Lingual membrane 53-12-1-12, central plate nearly square, wider at posterior 

 portion, tridentate, laterals bidentate, uncini, nearly straight slmrp spines. 

 (PI. 7, Fig. 35.J) 



