INDEX 
Abdominal pores, 271. 
Acanthias, \arva of, 216 (Figs. 288, 
289). 
waonnnedes, gill shields, 20; a fossil 
- shark of the Coal Measures, 79; 
‘structure of, 80, 81; A. wardii, 81 
(Fig. 87); shagreen and denticle of 
_ A. gracilis, 81 (Fig. 88); affinities 
of, 95; diagram of affinities, 98 
(Fig. 103); gill arches, 114. 
hckethinlinns, antiquity of, 9; fin 
spine and pectoral fin, 28, 29 (Fig. 
32); pectoral fin of Parexus, 42 
(Fig. 51), 44- 
ri ay ae wardii, teeth of, 82 
(Fig. 88 A). 
Mcaibbopleryelen, 166 (Fig. 171 “). 
ACANTHOPTERYGI, in classification, 9; 
as a subdivision of Teleocephali, 174. 
Acipenser, in classification, 8; antiquity 
of, 9, 166 (Fig. 171 4); swim-blad- 
der of, 22 (Fig. 13); description of, 
159-161; A. sturio, 160 (Fig. 165); 
eggs and breeding habits, 181 (Fig. 
194), 185; fertilization, 187; devel- 
opment of eggs, 203 (Figs. 249- 
264), 207; larval development of, 
221-223 (Figs. 296-302); heart, 
~ conus and bulbus arteriosus, tables, 
260; gills, spiracle, gill rakers and 
opercula, tables, 261; digestive tract, 
tables, 262 (Figs. 326-331); swim- 
bladder, tables, 264, 265 (Fig. 13); 
- genital system, tables, 266; urino- 
- genital ducts and external openings, 
tables, 267 (Figs. 332-337); excre- 
tory system and urinogenital ducts, 
tables, 271. 
285 
ACTINOPTERYGII, in classification, 8, 
147; description of, 155-178 (Figs. 
157-185 4A); Chondrosteans (Gan- 
oids), 155; fossil forms, 155-159 
(Figs. 158-164); living types, 159- 
178 (Figs. 165-185 4). 
Actinotrichia, 31, 33 (Fig. 39). 
Atheolepis, ganoid plates of, 24 (Fig. 
25), 25- s 
Agassiz, L., 37, 66, 107, 111. 
Agassiz, A., 224. 
Air-bladder, v. Swim-bladder. 
Allis, E. P., 50, 51. 
Alopias, 89; A. vulpes (thrasher shark), 
89 (Fig. 95). 
Alosa, eggs and breeding habits, 181 
(Fig. 197), 186. 
American Arthrodirans, 130. 
American Geologist, 80. 
Amia, in classification, 8; antiquity 
of, 9, 166 (Fig. 171 4); swim-blad- 
der of, 21, 22 (Fig. 14);_ sensory 
tracts in head dermal plates, and 
scales of, 50-52 (Figs. 64-68); 4 
calva, 51 note; a Ganoid with her- 
ring-like scales, 145; description of, 
163-165 (Figs. 167, 168); Mesozoic 
forms, 164, 165 (Figs. 169-171); 
heart, conus and bulbus arteriosus, 
tables, 260; gills, spiracle, gill rakers, 
and opercula, tables, 261; digestive 
tract, tables, 263; swim-bladder, 
tables, 264, 265 (Fig. 14); genital 
system, tables, 266;. excretory sys- 
tem and urinogenital ducts, tables, 
271. 
Amiurus, barbels of, 46, 47 (Fig. 58). 
Ammocetes, head of, 61 (Fig. 72 C), 
