Specimen No. 220 ([pl. 3, fig. 2]).
Illustrated: Amer. Geol., vol. 15, 1895, pl. 4 (drawing); Amer. Jour. Sci., vol. 13, 1902, pl. 3 (photograph).
This is one of the largest specimens showing appendages, and is developed from the ventral side. It shows some appendages on all parts of the body, but its special features are the exhibition of the shafts on the proximal ends of the antennules, the rather well preserved appendages of the cephalon and anterior part of the thorax, and the preservation of the anal opening. In the drawing in the American Geologist, the right and left sides are reversed as in a mirror, a point which should be borne in mind when comparing that figure with a photograph or description.
The shaft of the left antennule is best preserved and is short, cylindrical, somewhat enlarged and ball-shaped at the proximal end. It is 1.5 mm. long. The posterior part of the hypostoma is present, but crushed, and the metastoma is not visible, the pieces so indicated in Beecher's figure being the rim of the hypostoma. Back of the hypostoma may be seen four (not three as in Beecher's figure) pairs of gnathites, the first three pairs broad and greatly overlapping, the fourth pair more slender, but poorly preserved. The inner edges of the gnathites on the right side are distinctly nodulose, and roughened for mastication.
The outer ends of one endopodite and three exopodites project beyond the margin on the right side. The dactylopodite of the endopodite is especially well preserved. It is cylindrical, the end rounded but not enlarged or pointed, and bears three small sharp spines, all in a horizontal plane, one anterior, one central, and one posterior. The outer ends of the exopodites show about ten segments each (in 2.5 mm.) beyond the margin of the test, and from three to five setæ attached to the posterior side of each segment. These hairs are attached in a groove, well shown in this specimen. On the anterior margin of the exopodite there is a minute spine at each joint.
Measurements: Length, 38 mm.; width at back of cephalon, 19 mm.
Specimen No. 210 ([pl. 2, fig. 3]).
Illustrated: Amer. Jour. Sci., vol. 46, 1893, p. 469, fig. 1 (head and right side); Amer. Geol., vol. 13, 1894, pl. 3, fig. 7 (same figure as the last); Amer. Jour. Sci., vol. 13, 1902, pl. 2, fig. 1 (photograph).
This individual supplied the main basis for Professor Beecher's first figure showing the appendages of the thorax, the head and appendages of the right side having been taken from it, and the appendages of the left side from No. 206. Such of the endopodites as are well preserved show from three to four segments projecting beyond the test, and the dactylopodites have one or two terminal spines. The antennules are unusually well preserved and have about forty segments each in front of the cephalon, or an average of five to one millimeter.
Specimens 209 and 210 are on a slab about 7 × 5.5 inches, and with them are twelve other more or less well preserved individuals, all but one of which are smaller than these. Two of the fourteen are ventral side up on the slab, which means dorsal side up in the rock. Nine are oriented in one direction, two at exactly right angles to this, and three at an angle of 45 with the others. If the majority of the specimens are considered to be headed northward, then seven are so oriented, two northeast, one east, two south, one southwest, and one west.