NATURAL HISTORY MISCELLANY. 617 
the summer just past, I have paddled 650 miles up stream under 
the scorching northern sun, and 1,300 down stream in open canoes. I 
have made the first trip from Fort Youkon to the sea by the river 
Youkon ever made, and have geological notes of the whole of this 
distance, and have collected about 4,550 specimens, including some 
00 or 400 birds and mammals, and have got, I hope, some fine new 
Species of white fish. 
satis PUN 
ANSWERS TO CORRESPONDENTS. 
R. A. S., Wisconsin. — The worm you send came dried up and im- 
Possible to identify.’ It is probably an Ascaris, one of the round 
intestinal worms. Among the best works on the Microscope are 
cro 
delphia; Queckett’s Treatise on the Aoroecone, London; L. Beale’s 
How to Work with the Microscope, Philadelphia 
croscope, London; P. H. Gosse’s Evenings with the p; New 
ork. D. Appleton & Co. 
Wo He Ba elsto ig shells appear to be robust 
specimens of Physa sp et “ worm-like animals” are 
the larve of the Caddis-fly, o a son whose riis 
constructs a case of pas or pn of twigs and stic e othe 
Specimens were young Cra, , Cambarus Bartoni, y oud 
in brooks in the Middle weg pass ee We have found this o 
an allied species hiding under stones o: 
northern Maine. On the Aroostook oa they did great damage by 
undermining a dam, at or near Presque e Isle. The Cray-fish has under- 
Mined the levee at New Orleans and vicinity 
spinnerets), and catch on adjoining objects, serving as foundations for 
aw ; 
, AE, and. —Your Myriapod, which you say “ ae nee 
at this place eek, Md.) within a few years past, and has infes 
many houses,” is the Cermatia forceps, Wood. It is peo GEEA 
throughout the Eastern, and especially the warmer parts of the United 
States. Scarcely anything is known regarding its habits. 
AMERICAN NAT., VOL. I. 78 
