NORTH AMERICAN GRAPTOLITES 85 
exceedingly tangled maze of branches, most of which are of extreme tenuity, 
and cross and recross one another in inextricable confusion. A few larger 
branches are seen curving around and among the smaller. No thecz were 
observed, although certain indistinct crenulations may represent these struc- 
tures. Sicula and terminations, both proximal and distal, unknown. 
Horizon and locality. —Upper Calciferous, Summit, Nevada. 
CARYOCARIS SALTER, 1863. 
Quart. Jour. Geol. Soc., London, XIX., p. 139. Type, C. wrightzi. 
This genus, referred by its author to the Crustacea, was defined as fol- 
lows: 
“A long pod-shaped, bivalved carapace (with distinct hinge-pits), rounded 
anteriorly, subtruncate behind, and with the back and front subparallel. The 
surface is smooth, or with only oblique wrinkles near the margins, but with 
no parallel lines of structure. Body? Telson and appendages? 
“All I know of this pretty little Crustacean, an inch long and rather more 
than a third of an inch wide, is contained in the above note. I was fortunate 
enough to find the tubercles (Huxley found them also in Ceratiocaris), which 
I suppose indicate teeth, and corresponding pits at each end of a short 
hinge-fulcrum. 
“The shelly carapace is solid for its size; it appears to have a good deal 
of lime in its composition. The genus is evidently distinct, though so little 
is known of the entire form. 
“ Everywhere in the Skiddaw Slate district. I have named it after Mr. 
Bryce M. Wright.” 
It may be re-defined as follows: Polypary bilaterally symmetrical; proxi- 
mal portion possibly thecaphorous ; distal portion consisting of one (two?) 
median and two lateral appendages. Lateral appendages symmetrically 
disposed with reference to median line of polypary, apparently inserted on 
proximal portion through the medium of an elliptic body (“tubercles”’ of 
Salter); median appendage bilaterally symmetrical overlying superposed 
adjacent margins of lateral appendages. Texture yellowish-translucent, 
gauzy, resembling the wings of insects. 
The above description is based upon American specimens of the type 
species, the other species being known only in the form of the lateral append- 
ages. The substance of the polypary does not differ much from that of the 
Diplograpses in the same beds. In texture it resembles Dawsonia more 
nearly than any other genus, and the resemblance is increased by the pres- 
ence of a marginal filament. At present, however, there is nothing to show that 
Dawsonia actually represents the lateral appendages of species of this genus, 
and the relationship of the two genera may be summed up as follows: The 
Dawsonias are certainly comparable, as regards texture and general appear- 
