348 THE PALEONTOLOGY OF MINNESOTA. 
{Lingula (Glossina) deflecta. 
“The most elevated portion is at one-third the length from the beak, but the 
convexity of the valve is moderate and regular. 
“Dedicated to Mr. W. D. Hurlbut of Rochester, Minnesota, one of the earliest 
patrons of the Geological and Natural History Survey.” 
Recently Mr. W. H. Scofield found two other specimens of this species at the 
same locality in which the type was discovered. These specimens, however, add 
nothing to the interior characters, except that, near the anterior portion, the valves 
are strongly pitted, a feature, moreover, which is visible also on the type specimen. 
L. hurlbuti differs from L. crassa Hall,* the only species with which it need be 
compared, in being twice the size, and in having strongly elevated and compara- 
tively widely separated concentric lines of growth. In JL. erassa Hall, which also is 
referable to Phillips’s subgenus Glossina, the surface is described as being “appar- 
ently smooth, but, under a magnifier, exhibiting fine concentric and radiating strie.” 
Formation and locality—From the lower portion of the Galena limestone, in the quarries at Man- 
torville, and at Weisbach’s dam near Spring Valley. Minnesota. 
Collectors.—N. H. Winchell and W. H. Scofield. 
Mus, Reg. Nos. 393, 7674. 
LinavuLa (@LossinaA) DEFLECTA W. and S. 
PLATE XXIX, FIGS. 15-18. 
1892, Aprill. Lingula (Glossina) deflecta W. and 8. American Geologist, vol. ix, p. 284. 
Shell of medium size, subtriangular; lateral margins diverging more or less 
rapidly from an acute apex, to the broadly rounded and deflected anterior third. 
Shell substance thick, and marked by strong, irregular, concentric lines of growth, 
between which are numerous finer ones. In profile the line of junction of the 
valves is more or less convex, dorsally. Ventral valve flat or slightly concave 
medially, and strongly convex transversely. On the interior of the ventral valve 
there is a distinct but slightly elevated median septum, which originates near the 
apex, and terminates somewhat beyond the center of the valve, in front of which 
are the small, middle lateral muscular scars. Upon each side of the median sep- 
tum are the scars of the progressive central muscles, which gradually expand 
anteriorly, and terminate just above the middle lateral impressions. The vascular 
trunks bound the limits of the central scars, and meet just in front of the middle 
lateral impressions, where they are no longer defined. In front of these scars there 
is a low median elevation, with a broad shallow depression on each side, the latter 
being anterior to the vascular trunks and slightly pitted. Numerous irregularly 
radiating obscure lines back of the anterior margin. 
* Pal. New York, vol. i, p. 98, pl. xxx, fig. 8; 1847. 
