Page:Smithsonian Miscellaneous Collections, Volume 85.djvu/106

Rh

a, antennae; ap, anal plate; as, anal somite; c, carapace; d, doublure; en, endopodite; ex, exopodite; lb, labrum; m, mandibles; m ' , maxillae; m  , maxillulae; t'', telson.

(About ✕ 7.) Diagrammatic outline of ventral side with appendages. Much of the data on which this figure is based are shown by the specimens illustrated on plates 16 and 17. The exact form and position of the proximal joints of the cephalic limbs is unknown, but their general outline and position are about as outlined. The thoracic limbs, especially the endopodites, are well preserved in several specimens, but the exopodites are rarely seen and then only as faint and delicate impressions on the shale. The protopodites are fairly well defined, also the trunk segments and telson. The posterior endopodite and exopodite both differ from those anterior to them.