38 
THE APPENDAGES, ANATOMY, AND RELATIONS OF TRILOBITES. 
Fig. 9. — A restored composite of Isotclus maximus and /. latus. 
The exopodites are left out because entirely unknown. Drawn by 
Doctor Elvira Wood. Natural size. 
I was at once attracted by a specimen of Asaphus, from the Black Trenton Limestone (Lower Silurian), 
which has been much eroded on its upper surface, leaving the hypostoma and what appear to be the appendages 
belonging to the first, second, and third somites, exposed to view,, united along the median line by a longitudinal 
ridge. The pseudo-appendages, however, have no evidence of any articulations. But what appears to me 
to be of the highest importance, as a piece of additional information afforded by the Museum specimen, is 
the discovery of what I believe to be the jointed palpus of one of the maxillae, which has left its impression 
upon the side of the hypostoma — just, in fact, in that position which it must have occupied in life, judging 
by other Crustaceans which are furnished with an hypostoma, as Apus, Serolis, etc. 
The palpus is 9 lines in length, the basal joint measures 3 lines, and is 2 lines broad, and somewhat 
triangular in form. 
There appear to be about 7 articulations in the palpus itself, above the basal joint, marked by swellings 
upon its tubular stem, which is I line in diameter. 
