65 Canadian Arctic Expedition, 1913-18 
on the ridge at Bernard Harbour, July 3, 1916; by Jessup in a pool at White 
Horse, Yukon Territory, June 11, 1911; pond near New Rampart House, 
International Boundary and Porcupine river, June 12, 1911; lakes on Old 
Crow river flats, 40 miles north of New Rampart House, July 3, 1911; lakes 
on Old Crow river flats, 55 miles north of New Rampart House, July 10, 1911; 
lakes on Old Crow river flats, 60 miles north of New Rampart House, July 11, 
1911; small muddy pool near the Boundary line, 25 miles north of New Rampart 
House, July 17, 1911; pools at Fort Yukon, May 24, 1912; slough of Old Crow 
river, near New Rampart House, August 7, 1912. 
Notholca longispina (Kellicott). 
Collected by Johansen in a brackish lagoon west of Martin point, arctic 
Alaska, July 28, 1914; abundant in the lake south of Bernard harbour, Novem- 
ber 28, 1915; February 15, May 21 and June 12, 1916. 
FAMILY EUCHLANID. 
Mytilina ventralis (Ehrenberg). 
Salpina macracantha Hupson and Gossz, Rotifera, 1886, vol. 2, p. 84, 
pl. 22, fig. 6. 
In Jessup’s collections from a pond near New Rampart House, at the Inter- 
national Boundary and Porcupine river, June 12, 1911; lakes on Old Crow 
river flats, 40 miles north of New Rampart House, July 3, 1911; lake 48 miles 
north of New Rampart House, July 7, 1911. q ‘ 
Mytilina mucronata (Miiller). 
Salpina mucronata Hupson and Gosss, Rotifera, 1886, vol. 2, p. 83, pl. 22, 
fig. 1. 
A few specimens collected by Jessup in lakes on Old Crow river flats, 40 
miles north of New Rampart House, July 38, 1911. 
Euchlanis dilatata Ehrenberg. 
This species does not appear to be common in the Arctic; it was collected 
by Johansen among algae growing on stones in the river at Bernard harbour, 
on August 16, 1915, and in a pond at Chantry Island, Bernard harbour, on 
June 17, 1916; in Jessup’s material it occurred in fair numbers in a collection 
from lakes on Old Crow river flats, 60 miles north of New Rampart House, 
on July 11, 1911. 
Euchlanis pellucida, new species. 
Plate 2, figs. 1-5. 
The corona agrees with that of other species of the genus. The body is 
triradiate in cross section and has a high dorsal keel and broad, lateral, wing- 
Lke expansions. The ventral plate is nearly circular, slightly constricted 
anteriorly at the opening for the head; it is joined directly to the lateral plates 
without the intervention of a longitudinal sulcus as in other species of the 
genus. The foot is obscurely two-jointed; two long setae project from the 
dorsal side of the first foot joint. The toes are long, slender and nearly straight, 
slightly enlarged posteriorly, and end in rather blunt points; their length is 
more than one fifth of the length of the body. 
