286 Wisconsin Academy of Sciences , Arts , and Letters. 
Table 1. — Variations in form and size of C. brevispinosus —Cont. 
Length and form 
out. ter spine 
furca. 
Length of 
furca. 
Width of furca, 
1. terminal; 
2. base. 
Armature ter. 
joint 4th ft. 
Coll. C. D. M. 
No. 1497 
L. St. Clair. 
.05 mm. 
Thick, blunt. 
.1175 mm. 
1. .0212 mm. 
. .045 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. M. D. 
No. 1485. 
Butte des Mortes. 
.0175 mm. 
Thick, moderately 
blunt. 
.125 mm. 
1. .023 mm. 
2. .045 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 614. 
Coll, by E. A. 
Birge. Harshaw. 
.08 mm. 
Rather slender,not 
blunt. 
.15 mm. 
1. .023 mm. 
2. ,0475 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 1494. 
Baldwin, Mich., 
July, ’94. 
.038 mm. 
Thick at base, but 
tapering near apex 
rapidly. 
.096 mm. 
1. ,0225 mm. 
2. .04 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 1487. 
Long Lake. 
.0512 mm. 
Thick, moderately 
blunt spine. 
.1375 mm. 
1. .0225 mm. 
2. .015 mm. 
Inner ex. 1 ps. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 285. 
Green i^ake, July 
’91, pel. 
.0525 mm. 
Rather blunt, but 
not as thick as No. 
1487. 
.126 mm. 
1. .025 mm. 
2. 0375 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 1489 (1). 
L. Ontario. 
.05 mm. 
Thick, blunt spine. 
.1325 mm. 
1. .025 mm. 
2. .0475 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 1489 (2). 
L. Ontario. 
.05 mm. 
Moderately thick 
and blunt spine.. 
.1375 mm. 
1. .03 mm. 
2. .0525 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. C. D. M. 
No. 296 
Fond du Lac Riv¬ 
er, Oct., ’91. 
.0625 mm. 
Moderately thick 
spine, not blunt. 
.135 mm. 
1. .035 mm. 
2. .05 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. E. Birge. 
Slide 517 of C. D. 
M. 
L. Minoqua. Aug., 
’92. 
.0625 mm. 
Rather slender, 
not blunt. 
.15 mm. 
1. .02 mm. 
2. ,045 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll, by E. Birge. 
No. 516. 
L. Minoqua. Aug., 
’92. 
,049 mm. 
Short, moderately 
slender, not blunt. 
.1525 mm. 
1. .02 mm. 
2. .05 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
Coll. H. L. by C. 
D. M., July 28. 
Lake Winnebago. 
No. 1. 
.086 mm. 
Slender spine, not 
blunt. 
.175 mm. 
1. ,02 mm. 
2. . 047 mm 
Inner ex. 1 sp. 
br. ap. 2 sp. 
No. 2. Same coll, 
as No. 1. 
.06 mm. 
Moderately slen¬ 
der spine. 
.165 mm. 
1. .022 mm. 
2. .05 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
No. 3. Same coll, 
as No. 1. 
.055 mm. 
Slender. 
.13 mm. 
1. .025 mm. 
2. ,045 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
No. 4. Same coll, 
as No. 1. 
.058 mm. 
Moderately slen¬ 
der, not blunt. 
.1575 mm. 
1. ,02 mm. 
2. .0475 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
No. 5. Same coll, 
as No. 1. 
.0675 mm. 
Slender. 
.172 mm. 
1. .025 mm. 
2. .05 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
No. 6. Same coll, 
as No. 1. 
.065 mm. 
Moderately slen¬ 
der. 
.175 mm. 
1. .0225 mm, 
2. .05 mm. 
Inner ex. 1 sp. 
br. ap. 2 sp. 
