46 the appendages, anatomy, and relations of trilobites. 
The Appendages of Kootenia. 
Kootenia dawsoni Walcott. 
Illustrated: Walcott, Smithson. Misc. Coll., vol. 67, 1918, pi. 14, figs. 2, 3. 
One specimen figured by Doctor Walcott shows the distal ends of some of the exopo- 
dites and endopodites of the right side. He compares the exopodites with those of Neo- 
lenus, stating that the shaft consists of two segments, the proximal section being long and 
flat, fringed with long setae, while the distal segment has short fine setae. The endopodite 
best shown is very slender, and the segments are of uniform width and only slightly longer 
than wide. 
Measurements (from Walcott's figures) : Length of specimen, about 41 mm. Length 
of five distal segments of an endopodite, 7.5 mm. Since the pleural lobe is only 7 mm. 
wide, the endopodites, and probably the exopodites also, must have projected a few milli- 
meters beyond the dorsal test when extended straight out laterally. 
Formation and locality: Burgess shale, Middle Cambrian, on the west slope of the 
ridge between Mount Field and Wapta Peak, above Field, British Columbia. 
The Appendages of Calymene and Ceraurus. 
historical. 
All of the work on these species has been done by Doctor Walcott, who summarized 
his results in 1881. 
In the first of his papers (1875, p. 159), Walcott did not describe any appendages 
but paved the way for further work by a detailed and accurate description of the ventral 
surface of the dorsal shell of Ceraurus. He demonstrated the presence in this species 
of strongly buttressed processes which extend directly downward from the test just within 
the line of the dorsal furrows. One pair of these is seen beneath each pair of the gla- 
bellar furrows, each segment of the thorax has a pair, and there are four pairs on the 
pygidium. He pointed out also that these projections were but poorly developed on that 
part of the glabella which is covered by the hypostoma. He called them axial processes, the 
only name which appears to have been suggested thus far. 
The first announcement of the discovery of actual appendages in Ceraurus and Calym- 
ene was made by the same investigator in a pamphlet published in 1876 in advance of the 
28th Report of the New York State Museum of Natural History, the publication of the 
whole report being delayed till 1879. The results were obtained by the process of cut- 
ting translucent slices of enrolled trilobites derived from the Trenton limestone at Trenton 
Falls, New York. Since he summarized all the results of this study in one paper at a 
later date, it is not necessary to follow the stages of the work. 
A second preliminary paper was published in pamphlet form in September, 1877, and 
in final form in 1879, when the first figures were presented. 
In his important paper of 1881, Walcott reviewed all that was known of the appen- 
dages of trilobites to that time, and gave the results of seven years of study of sections of 
enrolled specimens. Slices had been made of 2,200 individuals from Trenton Falls, which 
resulted in obtaining 270 which were worthy of study. Of these, 205 were from Ceraurus 
pleurexanthemus, 49 from Calymene senaria, 11 from Isotclus gigas, and 5 from Acidaspis 
trentonensis. 
