PLATE VII 



TRIART1IRU8 BECKI Ckken (Packs 2(IG-2U9) 



FniUitK 1. — Veiilrul side of a large specimen ; sliowiiig, at each side 

 of the hypostoma, the antennules with tiieir single flagelluiii and strong 

 basal joint ; also the biranious cephalic appendages witli large gnatho- 

 bases ; the biramous thoracic limbs with gnathobases extending obliquely 

 backward in tlie axis of the trilobite; and the hyjiostoma, nietastoina, 

 and anus, in the median line. X 4. Utica Slate, Ordovician, near Rome, 

 New York. 



