448 Smith and Verrill—Dredgings in Lake Superior. 
Difference of 
STATIONS. Longitude. A ae 
hem. 8. Ss. . : 
Bee hala ane mate 243 4367+-008| -591+:°019 
Foose. St 042 2.844+°008| -2424 016 
Cambridge to San Francisco (sum), ...-______. 325 7-211+4°011 | -833+4-025 
¢ “ (direct, 325 Tl 
SERRE eas £30.) 90+°007 | -817+ O14 
WON, fii bie inne, = 0214°013 | -016+°029 
Cambridge to San Francisco, _._............. 325 7.190+°007 | -817+°014 
(C. to 0.)+(0. to S. L.)+(3. L. to 8. 5 A ee eae 7-1944°014 | -838+°027 
em 07 HO. te 8. Fo oT 7183+-013 | -819+°027 
MirteS.)+(8. Eto 8. PY css 7-211+4-011 | -833 4-025 
Cambridge to San Francisco (Mean of Me 325 7194+°006 | 82747012 
Art. LVIL— Notice of the Invertebrata dredged in Lake Superior 
in 1871, by the U. S. Lake Survey, under the direction of Gen. 
- B. Comstock, S. I. Smith, naturalist ; by S. L Smirx and 
A. E. VerRRILL. - 
(Published by permission.) 
During the explorations in Lake Superior, mentioned in the 
last number of this Journal (page 373) the following species 
were obtained, together with a number of minute forms, which 
have not been determined. 
_ full account of the expedition, with descriptions of the 
Species collected, will be published in the official report of the 
expedition. : 
RADIATA. 
In 32 fathoms, 
arbor, it was b 
In the deep dredging 
bottom of the clay in the ‘oe g 
while the dredge was near the 
surface. 
OLLUSCA, 
Limnea. A species allied to L. disidiosa Say, was abundant 
ng ora in 8 to 13 fathoms on the south side of St. 
tione 
__A very young specimen, apparently of 
fathoms among the Slate Islan 
