10 



This paper was sent to the publishers of the Boston Journal of 

 Philosophy before I had received your letter, and is now prob- 

 ably in press. 1 As to the labium superius or labrum of these 

 insects, I was contented with the observation of Latreille 

 (Hist, des Crust, et des Ins., Vol. 3, p. 158). He observes that 

 the "upper lip is concealed, corneous according to Knoch, 

 probably membranous." Knowing this, I made no search for 

 it. But it is the form of the mentum which takes the place of 

 the labium inferius or labium, that particularly interested me. 

 This part appears on examination to have a semicircular notch 

 in the edge, which divides it into two lobes, and the lobes them- 

 selves are ciliated. Have you observed this character? I 

 think I can hardly be deceived, and should like to know 

 whether this circumstance was as evident to you as to me. 

 The publishers have agreed to furnish an engraving of these 

 and some other insects which I have described for the number 

 to appear in April, when I shall gladly give you credit for the 

 observations you have made of the parts of the mouth, and 

 have only to regret that I cannot avail myself of them in the 

 present number. The insects which I am about to describe 

 are the two goliath species of Trichius, and one or two Ceto- 

 nia, genera closely allied to Chremastocheilus. Descriptions of 

 T. eremicola and seaber and Cetonia barbata are ready, and I 

 should like to obtain one other native Cetonia that has not 

 already been figured, to complete the paper. I found two 

 specimens of C. fulgida last summer, and you gave me C. 

 nitida ; but both have been described by Olivier. I have one 

 other, which I sent to Mr. Say, and he named it C. vestita ; 

 but it is of doubtful origin, and may have been introduced from 

 Europe. If you have any other native species than the four 

 named above, I should be very glad to borrow it for the pur- 

 pose of giving a -figure or description in the April number of 

 the Journal. 



1 [This paper did not appear in the Boston Journal of Philosophy, but was after- 

 wards sent to the Academy of Natural Sciences of Philadelphia and published in the 

 fifth volume of their Journal.] 



