Rotatoria som) 
The posterior segment of the body is roughly trapezoidal in oultline and 
cuspidate at the posterior angles; the margin is convex in the median portion 
and has a slight concavity at the angles. There is a well marked ‘constriction 
at the junction of the ventral plate and the posterior segment. The coxal 
plates are semi-ovate. 
__ The first foot joint is well marked and widest posteriorly; the second foot 
joint is nearly square. The toes are short, cylindric for one half their length 
and end in acute, conical points. 
Total length 126 yp, length of lorica 108u; length of dorsal plate 934; width 
93 uw; width of ventral plate 96 1; width of anterior points 58 »; length of toes 
27 yp. 
Lecane jessupt had some resemblance to L. brachydactyla (Stenroos), which 
is shown on plate 3, figs: 5, 6, for comparison. The differences are fairly evident: . 
L. brachydactyla has anterior spines and a straight, somewhat flexible dorsal 
margin, a double-curved ventral margin and the posterior segment is very 
simple in outline. JL. jesswpi was collected by Jessup in lakes on Old Crow 
river flats, 40 miles north of New Rampart House, on July 3, 1911; it was 
not abundant. 
Lecane luna (Miller). 
Cathypna luna Hupson and Gossn, Rotifera, 1886, vol. 2, p. 94, pl. 24, fig. 4. 
Apparently not common in the Arctic; it was collected by Jessup from two 
lakes on Old Crow river flats, 55 miles north of New Rampart House, on July 
10, 1911, and ponds on Old Crow river flats, 60 miles north of New Rampart 
House, on July 11, 1911. 
Lecane ungulata (Gosse). 
Cathypna minnesotensis Murray, Journ. Royal Micr. Soc., 1913, p. 345, 
pl. 18, fig. 18. 
A few specimens in a collection made by Jessup from two lakes on Old Crow 
river flats, 55 miles north of New Rampart House, on July 10, 1911. 
Lecane clara (Bryce). 
Distyla clara Brycn, Science Gossip, vol. 28, 1892, p. 271, text fig. 
Collected by Jessup from lakes on Old Crow river flats, 40 miles north of 
New Rampart House, on July 3, 1911, and in a slough of Old Crow river, near 
New Rampart House, on August les 1912. Only a few specimens were found 
in each collection. 
Lecane depressa (Bryce). 
Distyla depressa Brycn, Science Gossip, vol. 28, 1892, p. 271, text fig. 
Common in a collection made by Johansen among algae growing on stones 
in the river bed at Bernard harbour, on August 16, 1915. In Jessup’s col- 
lections from lakes on Old Crow river flats, 35 miles north of New Rampart 
House, on June 23, 1911; muskeg lake, 28 miles north of New Rampart House, 
on June 25, ie lakes on Old Crow river flats, 40 miles north of New Rampart 
House, on July 3, 1911; lakes on Old Crow river flats, 60 miles north of New 
Rampart House, on July 11, 1911; small muddy pool, 25 miles north of New 
Rampart House, on July 17, 1911. 
Lecane flexilis (Gosse). 
Lecane flexilis Harrine, Proc. U.S. Nat. Mus., vol. 47, 1914, p. 538, pl. 19, 
figs. 1-3. 
