486 



Sense buds, temperature, no 

 Skeleton, branchial, 322 

 dermal, 289 

 of Ateleaspis, 295 

 of Limulus, 296 

 of Astracoderms, 290 

 of Pteraspis, 293 

 of Tremataspis, 290 

 Stomodaeal commissure, 19 

 infolding, 38 



a,, IS, 60 

 nerves, 42 

 Stomodaeum, 42, 61 

 Swallowing reflexes, 189 



Tagmata, 26 

 Taste buds, 17 

 Tear duct, 260 

 Teleostomii, 386 

 Telocoele, 425, 433 

 Telopore, 22, 35, 246 



INDEX. 



Thymus, 263 

 Thyroid, 263 

 Tracts, general cutaneous, 87 



gustatory, 84 



lateral, 86 



longitudinal hsemal, 85^ 

 neural, 86 

 Tremataspis, 32, 359 

 Triple embryos, 284 

 Trochosphere, 34 

 Tunicates, 415 



Variation, 274 

 Vascular area, 24, 236 

 Vagus appendages, 19 



decussation, 191 



nerves, 20 



neuromeres, 19-67 



region, 19 

 Vertebrates, 381 

 Visceral arches, 263 



