PLATE XVI A. 
2 . 
5. 
6 . 
9. 
10 . 
13. 
14. 
Dalmanites (Cryph^us) comis. 
Page 41. 
The internal cast of a pyg'idium, enlarged to thi'ee diameters, and considerably restored. 
Upper Helderberg limestone. Cayuga, Province of Ontario. 
Dalmanites (Cryph^us) Pleione. 
View of the type specimen. 
Corniferous limestone. 
Page 41. 
Falls of the Ohio. 
Dalmanites (Cryphasus) Bootiii. 
See Plate 16. 
A small pygidium, showing the flattened marginal spines. 
Hamilton group. Darien, Genesee county. 
A larger pygidium, in which the marginal spines are longer and gently rounded, and the terminal 
spine acute. 
Hamilton group. Canandaigua Lake. 
The internal surface of a pygidium, in which the spines are broad and flat. 
Hamilton group. Near Geneseo, Livingston county. 
Similar view of a smaller pygidium, with more elongate spines. 
Hamilton grouj). Near Geneseo, Livingston county. 
A large pygidium, with spines of the normal character. 
Hamilton gi-oup. Canandaigua Lake. 
Three of the mai-ginal spines of the specimen repi-esented on plate 16, tig. 1, eidarged to three 
diameters. 
Dalmanites (Cryph^us) Boothi, v;ii-. Calliteles. 
See Plate 16. 
An impei'fect pygidium, I’eferred with some hesitancy to this variety. The long, acute spines are 
different from those in the normal adult foi’ms of either the species or the variety. No cei)hala 
accompanying such pygidia in the Hamilton shales have been observed. 
Hamilton group. Jaycox's Run, Livingston county. 
A pygidium with similar’ characters. The associated cephala bear’ the diagnostic characters of 
this vai’iety. 
Tully limestone. Goodwin’s, Cayuga Lake. 
A normal adult pygidium, enlai’ged to two diameter’s, showing the elevated, lanceolate marginal 
spines. 
Hamilton group. Canandaigua, Ontario county. 
The pygidium of the youngest individual observed (plate 16, fig. 5), enlarged to twelve diameter’s, 
showing the incurvature of the axis; the long, terete rnar’ginal spines, diminishing in length 
poster’ior’ly, and the undeveloped ter’minal spine. 
Hamilton group. Canandaigua, Ontario county. 
An individual in a slightly advanced stage of gr’owth (plate 16, fig. 6), enlar’ged to ten diameters, 
showing an approximation in the r’elative length of the spines. 
Hamilton gr’oup. Canandaigua, Ontario cotinty. 
An individual in a later stage of growth (plate 16, fig. 7), enlar’ged to nine diameters, showing the 
approximately equal length of the spines, except in the last pair’, and the incr’easing size of the 
terminal spine. 
