CiiAP. 6. 



INVERTEBRAL ANIMALS OF VERMONT. 



161 



FRESH WATER AND LAND SHELLS. 



widely distributed tlirough the United 

 States and Missouri Territory. 



lldix elcctrina. — GouLn. 



DESCRiinroN, — Sliell much depressed, 

 convex rdjove, shinino;, of a pale horn col- 

 or, sometimes yellowish or brownish, near- 

 ly transparent, with numerous very fine 

 inequidistant impressed lines or striic of 

 growth ; whorls three and a half, slightly 

 convex, with a well impressed suture, and 

 an impressed line immediately below the 

 suture, and parallel with it ; the last 

 whorl rapidly enlarging; aperture large, 

 slightly modiiied by the intrusion of the 

 penult whorl ; labruni sharp ; umbilicus 

 narrow and deep. Greatest breadth 02 

 inch ; least breadth O.IG inch; height 0.1 

 inch ; divergence IGo'^. 



Remarks. — This species much resem- 

 bles H.indcntuta above, but has the strioe 

 ziiuch more numerous, and usually one 

 whorl le.ss ; i)enealh the resemblance to 

 H. orhorca is equally striking, but the 

 umbilicus is not so wide. Without exam- 

 ination of both sides, it is very liable to 

 be confounded with one or the other of 

 the above species. It has been found in 

 Missouri, Ohio, Massachusetts, New York 

 and Vermont. 



Helix hiornata. — Say. 



Description. — Shell much depressed, 

 convex above, shining, with very fine ob- 

 lique incremental strife ; epidermis brown 

 horn color ; whorls five, slightly convex, 

 with a distinct but not deep suture ; the 

 last whorl much larger than the prece- 

 ding ; aperture very wide, much modified 

 by the intrusion of the penultimate whorl, 

 with an opaque white deposit within, 

 which is a little distant from the sharp la- 

 brum : the latter extends nearly to the 

 centre of the shell, projecting into the 

 small umbilicus. Greatest breadlli 0.5.5 

 inch ; least breadth 0.47 inch ; height 0.27 

 inch ; divergence 165". 



Rkmarks. — A single specimen only of 

 this species has been found in Vermont, 

 in Middlebury, It closely resembles H. 

 cdlaria, Mull. 



Helix fuUgiiiosa. — Griffith. 

 Desciuptkjn. -Shell globose-conic, with 

 very minute irregtilar oblique striee of 

 growth ; epidermis dark smoky brown ; 

 whorls four and a half, convex, with a 

 well impressed suture ; the last whorl 

 much larger than the preceding; aperture 

 nearly orbicular, not much modified by 

 the intrusion of the body whorl, with a 

 very thin deposit on the inside ; umbili- 

 cus deep, moderately wide. Greatest 

 breadth 0.05 inch ; least breadth 0.8 inch; 

 heigiit 0.5 inch ; divergence 135''. 

 Pt. I. 21 



Remarks. — This species is not com- 

 mon. It resembles the preceding, but 

 difliers in size, color, form of the aperture, 

 and greater width of the umbilicus. It is 

 the H. lucubriila of Say, a name ])er]iapg 

 entitled to preference, since that of Grif- 

 fith, although previously in use in cabi- 

 nets, was not published until after Say's 

 name had appeared in print. 



Helix multidentata. — B i n n e y . 



Description. — Shell much depressed, 

 conoid above, shining, reddish brown, 

 translucent, with very fine, somewhat reg- 

 ular impressed lines or stria? of growth ; 

 whorls seven, narrow, convex, often with 

 a very small impressed line revolving just 

 above the suture, which is deep ; the 

 whorls increasing but slightly in diame- 

 ter ; aperture narrow, very much modi- 

 fied by the intrusion of the penult whorl ; 

 labrum sharp ; teeth in rows, far within 

 the aperture, on its outer and lower half; 

 the rows are curved, with the convexity 

 towards the aperture, and contain from 4 

 to 6 closely approximate teeth, appearing 

 through the shell, under a magnifier, like 

 glass beads ; the number of rows varies 

 from two to four, of which one only is 

 visible from the aperture ; the umbilicus 

 is very narrow and deep. Greatest breadth 

 0.12 inch ; least breadth 0.11 inch; height 

 0.06 inch ; divergence 150^. 



Remarks. — This elegant little species 

 was discovered by Dr. Binney in Straf- 

 ford, and has since been found in Middle- 

 bury, also in New York, at Malone. It 

 has so little resemblance to any other 

 species, that comparison is unnecessary. 



Helix miimscula. — Binney. 



Description. — Shell depressed, whi- 

 tish horn color, with microscopic incre- 

 mental stria3 ; whorls more than four, very 

 convex, with a deep and very conspicu- 

 ous suture ; last whorl not much larger 

 than the preceding ; aperture nearly cir- 

 cular, not much modified by the intrusion 

 of the penult whorl ; labrum sharp ; um- 

 bilicus very large. Greatest breadth 0.08 

 inch; least breadth 0.07 inch; height 

 0.03 inch; divergence about 150°. 



R,e.marks. — This little species has been 

 found in Ohio and in this state. In size 

 and color it is like H. pulclie.lla, hut in the 

 other characters is at once distinguished. 



Helix linr.ata. — Say. 

 Description. — Shell very much de- 

 pressed and discoid, with parallel equi- 

 distant raised revolving lines ; epidermis 

 green ; whorls four and a half, very con- 

 vex, narrow, with a deep suture, last 

 whorl very little enlarged ; aperture lu- 

 nate, very much modified by the intrusion 



