NORTH AMERICAN rAL^ONTOLOGV. 267 



Packard, A. S. Geological Extiuctiou iiud some of its Apparent 

 Causes. (Araer. Nat., vol. xx, pp. 29-40, January, 188G. Philadel- 

 phia.) 



" That there is a limit to the age of species as well as to individuals almost s^oes 

 without sayiug. As there is iu each individual a youth, manhood, ami old 

 age, so species and orders rise, culminate, and decline." (This view was 

 first propounded by Prof. Alpheus Hyatt. — Ed.) The causes, however com- 

 plex, are, iu the case of plants and animals, apparently physical ; they are 

 general and pervasive in their eftects, and have been in operation since life 

 began ; there have been critical periods in paleontological as well as geo- 

 logical history, and periods of rapid and wide-spread extinction as well as 

 continual, progressive dying out of isolated species. 



Packard, A. S. Causes of the Extiuctiou of Species. (Pop. Sci. 

 Monthly, vol. xxix, p. 429, July, 188G. New York.) 

 Abstract of. 



Packard, A. S. Discovery of the Thoracic Feet in a Carboniferous 

 Phyllocaridan. (Read before the American Philosophical Society, 

 February 5, 1886.) Proc. Amer. Phil. Soc, Philad., vol. xxiii, pi). 

 380-383, pi. p. 380. 



Describes Cryptozoe problematicus Packard. 



Packard, A. S. Discovery of Lamellate Thoracic Feet in the Phyllo- 

 carida. (Amer. Nat., vol. xx, pp. 155, 156, February, 1886. Phila- 

 delphia. 



Describes the thoracic limbs and regards the parts preserved as the homolognes 

 of the exopodites of Nebalia. The author named the specimen in M8S. 

 Cryptozoe prohlimaticus, as he was in doubt as to its affinities. A descrip- 

 tion of the new genus and species will appear hereafter, with figures. 



Packard, A. S. [See Dames.) 



Panton, J. Hayes. Fragmentary Leaves from the Geological llecords 

 of the Great Northwest. A paper read before the Society on the 

 evening of 24th January, 1884. (Manitoba Hist, and Sci. Soc, ^ in- 

 nipeg. Transactions, No. 4, season 1883-'84, i)p. 1-9, 1884. Winni- 

 peg.) 



Mentions vertebra;, thigh bones, and a hip joint of "cretaceous dinosaurs" ?. 

 Mentions also the occurrence of various invertebrate Laramie and Cre- 

 taceous fossils. 



Panton, J. Hayes. Gleanings from Outcrops of Silurian Strata in the 

 lied Hi ver Valley. A paper read before the Society on the evening 

 of 27th November, 1884. (Manitoba Hist, and Sci. Soc, Winnipeg. 

 Transactions, No. 15, season 1884-'85, pp. 1-13, 1884. Winnipeg.) 

 Gives lists of Silurian fossils occurring in the vicinity of Winnipeg. 



Panton, J. Hayes. Notes on the Geology of some Islands in Lake 

 Winnipeg. A ])aper read before the Society on the evening of Thurs- 

 day, 28th January, 1886. (Manitoba Hist, and Nat. Sci. Soc, Win- 

 nipeg. Transactions, No. 20, season 188(>, pp. 1-10, 1886. Winnipeg.) 

 Mentions the occurrence of a number of genera of Silurian fossils. 



