19 [ Information respecting Botanical Traveller*. 



posterior false molar of a similar form and in like juxtaposi- 

 tion with the true molars, as the tooth in the present fossil, 

 (on the supposition that it immediately preceded the true 

 molars) has the next false molar so small as it must have been 

 in the fossil on that supposition. 



3. Tiro molars of a small Mammal most nearly resembling 

 those of the Insectivorous Bats. (Fig. 3.) 



One of these small grinders (fig. 3, a) has its crown com- 

 posed of four triangular prisms, placed in two transverse rows, 

 with an angle turned outwards and a side or flat surface in- 

 wards, the summits being sharp-pointed. The exterior prisms 

 are the largest. The crown swells out «. rig. 3. a. 

 abruptly above the fangs, defending - 

 them, as it were, by an overhanging 



ridge. There is a small transverse emi- ^ 



nence or talon at the anterior part of Twice nat * size 



the crown ; and a very small tubercle is placed between the 



bases of the two external prisms. 



The second molar (fig. 3, b) differs from the preceding in 

 having the two posterior prisms suppressed, and replaced by a 

 flattened triangular surface. The anterior prisms are present, 

 and their apices project far beyond the level of the posterior sur- 

 face. There is a small ridge at the anterior part of the tooth. 



These teeth agree more nearly with the antepenultimate 

 and last molars of the larger Insectivorous Bats than w r ith any 

 other teeth with which I have as yet compared them : they 

 differ chiefly in the presence of the small tubercle at the basal 

 interspace of the exterior prisms. 



XXII. — Information respecting Botanical Travellers. 

 Mr. Schomburgk's recent Expedition in Guiana. 

 In our first volume, p. 68, we communicated the accounts which 

 we had received from Mr. Schomburgk up to the autumn of 1837, 

 informing us of his intention to prosecute his researches to the east- 

 ward and towards the sources of the Orinoko. We shall now have 

 the satisfaction, from his arrival in this country, to present our readers, 

 in the present and subsequent Numbers, with the narrative of his 

 proceedings up to the time of his return to Georgetown, the capital 

 of British Guiana. 



