164 Mr. S. S. Saunders's Descinption, Sfc. 



as being found in Guadaloupe, is stated to have two valves of 

 unequal size, playing in like manner upon a single hinge, the 

 larger one taking its rise from the hinder part of the smaller, and 

 being so adapted that it would seem to cover this latter as well as 

 the margin of the orifice itself. Baron Walckenaer, alluding to 

 these nests, in his remarks under the head of M. nidulans, in the 

 ''Suites a BulFon," infers, that the insect by which they were con- 

 structed was probably different from the ordinary species observed 

 at Jamaica, of whose economy some further details have recently 

 been laid before this Society by Mr. Sells. At all events the de- 

 scription of Olivier so strongly coincides with the appearances 

 presented by Brown's figure, that there can be little hesitation, 

 I think, in referring them to the same species. The length of the 

 nests also appears to correspond. Brown's figure measuring 4| 

 inches, and not c5|, as through some inadvertence stated by 

 Baron Walckenaer. 



On my return to the Mediterranean, I hope to have further 

 opportunities of observing the habits of the Mijgale lonica, and 

 perhaps of detecting the insect in the act of building, which may 

 enable me hereafter to lay before the Society some additional 

 particulars connected with the construction of these ingenious 

 retreats. 



The accompanying figures upon Plate IX., for which I am in- 

 debted to the kindness of Mr. W. W. Saunders, exhibit — 



1. The insect, of natural size. 



2. The eyes. 



3. External view of right mandible, magnified. 



4. Internal view of ditto. 



5. Hooked process of ditto, apart. 



with a, the small hole from which the poison is sup- 

 posed to issue. 



6. Portion of fore leg, magnified. 



7. Portion of hind leg, magnified. 



8. Bicuspidate process of tarsus, with claws. 



9. Upper portion of nest, with lid partly open (side view). 



10. Ditto ditto (front view). 



11. Longitudinal section of ditto, and of operculum. 



12. Lower portion of nest, with smaller valve open. 



13. The same (side view). 



14. Lower portion of another nest reversed, the valve closed. 



