Pulmonifera of Maine. 



27 



parietal laminffi. With an ordinary magnifying power, small 



swellings are seen at close intervals along these laminae, which 



when magnified four hundred diameters are seen to be surmounted 



with from five to ten sharp spines pointing toward the aperture : 



{Fig. 66.) These swellings 



appear to coincide in number 



and position with the raised 



ribs without the shell, though 



they are not formed at the 



same time; for as these laminfe 



approach the aperture they 



become attenuated and dis- Fig GG 



appear. The surface upon which these lamina? rest is granulated, 



and not smooth as is generally the case with the interior of shells. 



It is difficult to imagine the use of these spiny projections, unless 



they may act in some way as points of resistance to the animal 



for the support of a very heavy shell. 



Buccal plate, (Fig. 67,) slightly arcuate, cutting edge \^- -^/ 



straight, minutely notched. --^ 



Lingual membrane, 78-13-1-13, central plate large, square. Fig. 67. 



tridentate, central denticle long as plate ; Laterals square, outer posterior mar- 

 gin raised into a tooth-like projection, bidentate ; uncini broad, short, den- 

 ticulated. (P/. 8, i'7r7. 68.) 



PUNCTIN^. 



Punctum. NOV. gen. 



From the peculiar conformation of the buccal plate, divided 

 into sixteen distinct pieces, and the character of the lingual den- 

 tition corresponding closely with Carychium exiguum and not 

 unlike Alexia myosotis. I am not only inclined to propose a new 

 genus for this species, but to raise it also to the importance of a 

 sub-family, trusting that a more extended examination of its 

 habits and structure will sustain me in this step. 



Punctum minutissimum, Lea. {Fig. 69.) 



Abundant throughout the southern portions of the State. Their 

 extreme minuteness renders them difficult of detection ; in one 



