404 NEW YORK STATE MUSEUM 
proximal end a transverse section of the lamina is seen and a broad cleft 
exposed while at the distal end the interior margin of one of the laminae 
is pushed over the other. A third element of the telson consists of a thicker, 
narrower longitudinal plate intercalated between the dorsal and ventral 
plates along the median line. The transverse section at the proximal end 
of the telson fragment gives the view reproduced in text figure 91. 
The median plate is seen resting on one of the ventral plates without being 
attached to it, and beneath it the sections of two inclined plates are notice- 
able. The latter were, we surmise, originally the supporting plates of 
the median plate, as shown in reconstruction in text figure 92. While 
this structure reminds one of the T-like keel of the underside of the telson 
of Eurypterus, it differs from the latter in being introverted between the 
two plates instead of standing out on the ventral side. 
Along the median line of the middle plate, just above the median 
ventral cleft, a suture passes: The presence of the cleft and of the middle 
plate with the median suture, all combine to suggest that the two halves 
of the broad telson may have been capable of being bent slightly in the 
back stroke of the flapping telson. 
The margin of the telson has a thickened rim which is cracked at 
irregular intervals, as in Eurypterus, giving it a serrate appearance. 
The third fragment is the proximal portion of a leg [text fig. 93]. 
It retains the coxa with the gnathobase and portions of the three suc- 
ceeding segments. The form of the coxa would indicate that it be- 
longs to an endognathite. Its form is elongate quadrangular; the man- 
ducatory edge is slightly curved and bears a series of nine or more, rather 
blunt teeth, which become flatter posteriorly. The part adjoining the 
manducatory edge is furnished with a pavement of flat polygonal scales 
which are elongate and slightly imbricated near the anterior edge. The 
rest of the coxa bears small subcircular flat scales and minute tubercles. 
The outlines of the following segments of the leg are very faint and can 
be made out only with difficulty by turning the specimen to the lght. 
The surface of these segments is finely granulate. 
