VI. 



Pagb. 

 Haltsites Catenulatus 319 



HoMOLONOTCS Deli'hinocephalus 319 



Hudson River Group. — Lower Silurian 18 



Hydra. — A small fresh-water animal related to the coral building Po- 

 lypi. Hydra, a water-serpent, with fifty heads, slain by 



Hercules 117 



Hystrix Dorsata.— The Porcupine 365 



Hare 359 



Hall — Professor T., his article on Tellinomya 390 



IsoTELUs.-;— A genus of trilobites ; Greek, isos, equal, and telos, end, in 



allusion to the equal extremities of the fossil 45 



IsoTELUs GiGAS. — A. large trilobite of the lower Silurian rocks 45, 46 



IcHTHYOCRiNUS. — A genus of Encrinites; Greek, ichthus, a fish, and 



krinos, a lily 69 



IcHTHYocRiNUs LAEVis. — The smooth Ichthyocrinus, a beautiful encri- 



nite of the Niagara limestone 69 



Infra-orbital cavities of Deer 96 



Laubentian Eocks. — So called after the Laurentian Mountains, a range 



of low hills on the north shore of the St. 



Lawrence 18 



Lawrencian Formation. — The deposit of clay, sand and gravel, in the 



valleys of the St. Lawrence and Ottawa, 



containing marine organic remains 336-334 



LiNGULA. — A genus of Brachiopods 35-36 



Leptena. — A. genus of Brachiopods ; from the Greek Leptos, thin 40 



Leptena sericia 41 



Lachrymal Sinus , 96 



Leptena Transversalis 138 



Lepi'ena Subplana 138 



Leptena Deltoidea 205 



Lupus. — Latin, a wolf 209 



LuTEA Canadensis. — The Canadian Otter , , . . 228 



Leidy, Prof. — Notice of his descriptions of fossil fishes and mammalia. 239 



Lea, Dr. Isaac, L.LD., Philadelphia, his works on genus Unio 240 



Lynx. — The Loup Cervier, Lynx Canadensis 24*7 



Lynx Rufus. — The Wild Cat 249 



LiNGULA Quadrata 318 



Lawrencian formation 336 



Lepus Americanus. — The Northern Hare 369 



Logan. Sir Wm. E. See Davis' Notes to tlie article on American Geo- 

 logical History, ei seq 4Q0 



Medina Sandstone.— A division of the lower Silurian. Medina, the 



name of a locality in the State of New York. . 21 

 Murchisonia. — A genus of gasteropods, named in honor of Sir Rode- 

 rick. I. Murchison, at present director of the Geologi- 

 cal Survey uf Great Britain 42 



MuRCUisoNiA gracilis 42 



