INDEX 



325 



Infiaoil)ital canal, 242, 261, 274, 277; 



nerve to, 224, 242, 279 

 Infraorbital plate, 53, 57; absence of, 57 

 Infundibulum, 221, 233, 236 

 Inner buccal ampullae, 262, 279 

 Inner zone, 70 

 Integument, 23, 26; in Elasmobranchs in 



general, 26-38; in Eeptanchm, 23-25 

 Interarcuales muscles, 90, 92, 106; dorsal, 



92, 106; lateral, 92, 106-107 

 Intcrbranchial muscles, 91, 105-106, 149, 



151 

 Intercalary plate, 48, 72 

 Intercostal arteries, 169, 193 

 Intermediate lobe of hypophysis, 234 

 Internal branchial aperture, 37, 147, 154; 



relation to gill rakers, 154 

 Internal carotid artery, 165, 182-183; fo- 

 ramen of, 53; relation to ramus auas- 



tomoticus, 165, 183 

 Internal flexor muscle, 95, 112 

 Internal mandibular nerve, 243 

 Internal pretrematicus (IX), 225 

 Internal (anterior) rectus muscles, 90, 99; 



nerve to, 100, 239; origin of, 99 

 Interorbital canal, 44, 205 

 Interorbital vein, 198, 205 

 Intima, 170 



Intraintestinal artery, 166, 188 

 Intraintestinal vein, 200, 210, 212; in 



Zygaena, 210 ; relation of, to subiutes- 



tinal vein, 210, 212 

 Iris, 258, 267; of light organ, 29 



Kidney, 287, 289, 292; arteries to, 169, 

 193; ducts of, 294-296; finer anatomy 

 of, 296; in Elasmobranchs in general, 

 292-294; in Heptanchus, 287; in rays, 

 292 ; metamerism of, 292, 299 ; metamor- 

 phosis in male, 292, 302; sexual differ- 

 ences in, 289, 292; veins of, 200, 208, 

 209, 210 



Labial cartilage, 67, 68; in Heptanchus, 

 68; in Hexanchus, 68 



Laemargus, photophores of, 29 



Lagena, 261, 272; nerve to, 273 



Lamina terminalis, 239 



Lamna cornubica, 9 ; muscles in tail of, 97 



Lateral (abdominal) artery, 168, 179 



Lateral abdominal system, 202, 204, 214, 

 217; history of, 214-215 



Lateral abdominal vein, 202, 213; tribu- 

 taries to, 202, 213-214 



Lateral bundles, 97 



Lateral cutaneous veins, 203, 214, 217; 

 relations of, 203, 217 



Lateral fin-fold, 14, 15, 214 



Lateral fin-fold theory, 14; evidence for, 

 15 



Lateral hypobranchial artery, 162-163, 

 178 



Lateral line, 264, 274, 275, 276; in Acan- 

 thias, 276; development of, 264, 275- 

 276, 278; function of, 279; in Heptan- 

 chus, 7, 89, 261; nerves to, 225, 242, 243, 

 278; section through, 278 



Lateral plate, 96, 109 



Lateral pterygial artery, 191 



Lateral pterygial vein, 213 



Lateral septum, 97 



Lateral ventricles, 236 



Lateralis nerve, 225, 245, 278 



Lens cell of light organ, 29 



Lens of eye, 267; development of, 269 



Leopard shark (Triakis), color of, 26 



Levator hyomandibularis, 103 



Levator labialis muscles, 93, 100-101 



Levator maxillae, 90, 101, 102; nerves of, 

 241; relation of, to first dorsal constric- 

 tor, 90 



Levator rostri, 104 



Lipochrome, 27 



Lipophores, 27; in Heterodontus, 27 



Littoral, 1 



Liver, 124, 137; artery to, 166, 187; ducts 

 of, 124, 137; lobes of, 124, 137; oil of, 

 137; veins of, 211-212 



Lobes of vagus, 236, 237 



Lobi inferiores, 233 



Locomotion: caudal, 13; pectoral, 12, 13 



Longitudinal canal of epididymus, 301 



Lymphatic vessels, 218 



Lymphocytes, 133 



Lymphoid organ, 133 



Macula neglecta of ear, 273; hair cells of, 

 273; nerve to, 273 



Mandible, 63, 92, 279; muscles to, 92, 93- 

 94 



Mandibular ampullae, 279 



Mandibular arch, 44, 45, 62, 63; articu- 

 lation of, 45, 63; attachment of, in 

 Heptanchus, 45; in embryo, 62; parts 

 of, 45, 62 



Mandibular branch (V), 223, 240, 241; 

 ganglion of, 240; motor fibers of, 240; 

 sensory fibers of, 240 



