LYMN&=:IDZ OF NORTH AMERICA. 393 
appears to be a recognizable race of catascopium, characterized by an 
elongated, narrow shell, flat-sided whorls and a narrow aperture. 
Galba catascopium adamsi, Var. Nov. Plate XLII, figures 5-8. 
Lymne@a catascopium Waker, An. Rep. Geol. Surv. Mich., 1908, p. 291, 
1909.—GLEASON, 1. c., p. 64, 1909. 
SHELL: Thin, narrow, much elongated; periostracum yellowish 
or whitish horn; sculpture coarser than in typical catascopium; whorls 
6-614 very flatly rounded, very slowly increasing in diameter but rapid- 
ly increasing in length; spire very long, usually longer than the aper- 
ture, narrow, acute, the whorls very flatly rounded; sutures shal- 
low; outer lip but slightly thickened within; aperture narrow, very 
elongate-ovate, narrowed above and below and frequently sharply 
angled; inner lip rather wide, flatly reflected and tightly appressed to 
the columellar region, usually completely closing the umbilical chink; 
there is a distinct, oblique columellar plait and the parietal wall is 
covered with a heavy, wide callus ; axis twisted. 
Length. Breadth. Aperture length. Breadth. 
16.00 8.00 9.00 4.00 mill. 
15.00 7.00 7.50 3.00 
15.60 7.00 8.00 3.50 
Types: Chicago Academy of Sciences, four specimens, No. 
24511; cotypes, coll, Bryant Walker. 
Tyre Locatity: St. Clair flats, Detroit, Michigan. 
ANIMAL: Not differing from typical catascopium. 
Jaw: As in catascopium. 
RapuLa: Not differing from typical catascopium. There is little 
variation, there being nine laterals in all the specimens examined. 
GENITALIA: (Plate XV, fig. F, 1-3). Not differing essentially 
from these organs in typical catascopium. In one specimen from the 
St. Clair flats, the penis-sac retractor was double (3). The measure- 
ments of the genitalia will be found under typical catascopium (p. 385) 
where they are listed for comparison with the typical form. 
RANGE: Adamsi has not been seen outside of the state of Michi- 
gan and is, hence, confined to the Canadian Region. 
RECORDS. 
MicHiIcAN: St. Clair flats, Wayne Co.; small island in Tobin Harbor, 
Isle Royale (Walker). 
Ecotocy: “Apparently most frequent in shallow water in places 
sheltered from the waves.” (Isle Royale) St. Clair flats (Detroit). 
ReMArKS: The race here separated from catascopium offers 
characters which easily separate it from the typical form, which is 
always wider, with a shorter, wider spire and a more ovate aperture. 
