JOURNAL OF PROCEEDINGS. 158 



W. M. Gabb, from the Author; Notice sur les travaux d'Anatomie et de 

 Zoologie — Specimen Charact. Typograph. S. Concil. Christ, notn. Pro- 

 pag., from Dr. S. Pollute. 



Dr. Shumard rend a paper, entitled "The Primordial Zone 

 of Texas, with Descriptions of New Fossils." Referred to a 

 committee. 



Dr. Shumard exhibited his geological map of Texas pre- 

 pared from investigations made by the Geological Survey. 

 He stated that the geological maps of Texas that had been 

 published were necessarily quite imperfect. Upon the map 

 exhibited this evening he had endeavored to lay down, so far 

 as determined, the general boundaries of the Primordial, 

 Lower Silurian, Carboniferous, Coal Measures, Cretaceous, 

 Eocene and Miocene Tertiaries, and Post Tertiary Formations. 

 He had not been able to recognize any Jurassic or Triassic 

 beds in Texas, though he did not wish to be understood as 

 saying that such rocks were altogether absent there. He had 

 examined fossils from a number of localities claimed to be of 

 Jurassic age, and found them to be of unequivocally Creta- 

 ceous species. 



Dr. Engelmann gave an account of the singular series of 

 thunderstorms which occurred yesterday, March 31st. 



After a thunderstorm on the 29th, between 7 and 8 o'clock A. M., with 

 south wind and a little rain, the barometer continued to fall till 121 P.M., 

 when the wind suddenly veered to the west, blowing quite hard, and pre- 

 cipitating 0.73 inches of rain, the barometer rising:. On the morning of 

 the 301 h the thermometer marked 36 Q , a fall of 30° since noon of the pre- 

 vious day; the barome'er rose, the sky was clearing off with N.W. and 

 then N.E. wind. On the morning of the 3lst the sky was clear, the tem- 

 perature 45°, wind E. After 9 o'clock the scene changed, and a succes- 

 sion of thunderstorms ensued, continuing from 10 A.M. till 10 P. M., with 

 a fall of 2.34 inches of rain; the wind veering around suddenly from 

 west to east, north, west, again east and south-east ; the barometer rising 

 and falling most extraordinarily, especially between 2 and 2±_ o'clock P. 

 M., when the rain poured down in torrents. The temperature remained 

 all the time steadily between 42° and 43°. 



At 2 P.M. the barometer indicated 29.485, wind E., force 3. 



" 2.5 min. " " 



tt 2.10 " " " 



u 2.\o " « " 



tt 2.20 " w " 



<< 2.25 u " " 



" 2 2S " " " 



'' 2.30 " " '* 



tt 2.40 " " " 



Such rapid fluctuations of the barometer Dr. Engelmann had never be- 

 fore observed. 



Mr. Holmes presented from M. Conrad, Esq., a mass of 

 Lithostrotion Canctdense from St. Louis Co., Mo. 



