LETTER OF MAY 15TH, 1859. 19 



give you more pleasure. Since completing the Synopsis of 

 the Sphingidce, I have been working at the " Micros" or 

 rather the Tineina. I could have accomplished much 

 more than I have, had I not suffered during last summer 

 from several weeks of illness that confined me to my room. 

 The majority of my summer observations were lost, or at least 

 their results. During the fall, however, I managed to collect 

 and described about sixty larvae. The perfect insects have 

 been appearing during the last week or two, but many I fear 

 have died in the pupa state. I will give you a list of the 

 genera I have recognized ; and some of the species correspond 

 so remarkably to your descriptions of some of the British 

 species, as to induce me to believe they must be identical. 



The following are some of the genera, which I have recog- 

 nized beyond any doubt : 



Plutella ; Coleophora ; Gracilaria ; Ornix ; Cosmopteryx, 

 a most beautiful species, which I think must be very like 

 Drurella ; Tischeria, and some other species belonging to 

 the same family, which I will not venture at present to 

 designate generically ; about fifteen species of Lithocolletis ; 

 and some Nepticula larvas, which have not yet produced 

 perfect insects. I have just finished the study of a species 

 about which I wish to write to you specially.* It has all the 

 structural characteristics of Asyclina terminella, except that 

 the submedian vein of the anterior wings is not furcate at the 

 base, and that the labial palpi are not drooping. The 

 specific description of Terminella corresponds, too, most 

 remarkably, to the species under consideration. I observe 

 you say that Terminella is a discrepant species in the genus 

 under which it is placed, and that its embryonic history is 

 unknown. I will, therefore, give you briefly the larval history 

 of the species in hand, hoping you have by this time ascer- 

 tained something respecting Terminella, and can inform me 

 whether they correspond, and whether the species has been 

 removed from the genus Asychna. 



* Afterwards recognized as an Antispila and described as A. Nysscefoliella, 

 Proc. Acad. Nat. Sci. Phil. Jan. 1860. H. T. S. 



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