Mr. J. B. C. Lucas presented a fragment of a fossil bone, found 

 on the headwaters- of the Colorado river, in Texas. It was be- 

 lieved to be a portion of the fibula of a large tertiary saurian. 



Dr. Engelmann read the following paper, comparing the pres- 

 •ent spring with that of 1842 : 



The extraordinarily mild weather of this spring, and the consequent 

 earlj development of vegetation, merit a thorough consideration of these 

 phenomena, and a comparison with the only other very early spring in 

 St. Louis, since observations have been recorded, that of 1842. 



The temperature of March, 1842, was 55°, which is nearly two degrees 

 higher than that of the past March, which was 53°. 2, and nearly twelve 

 degrees higher than the average for March. February, 1842, was scarcely 

 warmer than the average, and March was by no means warm in its first 

 part, the temperature falling several degrees below the freezing point, 

 every night, from the nth to the 13th; but from the i6th on it began to 

 rise, reaching between 70 and So degrees six times, and between So and 86 

 five times ; while last March, my thermometer reached between 76 and 77 

 as the highest of the month, only three times. This accounts for the more 

 rapid development of vegetation in the latter half of that month. The 

 shad-bush (^Amelanchier) was in full bloom on the rocky slopes between 

 the Arsenal and Carondelet (where at that time it abounded) on the iSth. 

 On the 19th I recorded plum and peach trees in bloom in the gardens in 

 the city; on the following day cherry and pear trees were noted in bloom, 

 and on the 21st the first blossoms were found on the two early apple trees 

 in the bishop's garden, at the corner of Walnut and Second streets, which 

 I used to observe every year as among the earliest in bloom. On March 

 26th the red-buds were seen in bloom in the woods; on the next day, the 

 lilacs in the gardens showed the first flowers, and on the 28th the apple 

 trees everywhere in the gardens in and about town were recorded in full 

 bloom. On the last day of the month, lilacs were in flower in town, and 

 paw-paws, black and red haws in the woods around, and dogwood began 

 to show its conspicuous white flower-like involucral bracts. 



It appears that this year we are a few days later, undoubtedly caused by 

 the cooler weather since the middle of the month, though it was inter- 

 spersed with a few warm days. 



As it is, this March and that of 1S42 were the only March months in 46 

 years in which the temperature rose to more than 50 degrees, and during 

 which the peach trees passed their flowering periods and the apple trees and 

 lilacs began to bloom. 



Let us now look at the month of April, 1842, succeeding that early 

 March. Its mean temperature was 63'=, being seven" degrees above the 

 average, and although we have had several as warm Aprils, in none did 

 the vegetation make such rapid progress, owing to the start it received in 

 March. I will only state that my notes prove our wild crab-apple to have 



