Illustrated: Walcott, Smithson. Misc. Coll., vol. 67, 1918, p. 145, pl. 21, figs. 1, 2.
Walcott figured one individual of this species showing long slender antennules projecting in front of the cephalon. It is of especial interest because one of the antennules shows almost exactly the same sigmoid curvature which is so characteristic of the related Triarthrus. The individual segments are not visible.
Measurements: The specimen is 23 mm. long and the direct distance from the front of the head to the anterior end of the more perfect antennule is 9.5 mm. Measured along the curvature, the same antennule is about 11 mm. long.
Horizon and locality: Same as the preceding.
The Appendages of Kootenia.
Illustrated: Walcott, Smithson. Misc. Coll., vol. 67, 1918, pl. 14, figs. 2, 3.
One specimen figured by Doctor Walcott shows the distal ends of some of the exopodites and endopodites of the right side. He compares the exopodites with those of Neolenus, stating that the shaft consists of two segments, the proximal section being long and flat, fringed with long setæ, while the distal segment has short fine setæ. The endopodite best shown is very slender, and the segments are of uniform width and only slightly longer than wide.