Having upon a former occasion made some remarks upon the 

 Order Omaloptera and taken a view of the structure, which at 

 that time could not be fully illustrated in consequence of the 

 rarity of the species then investigated, we shall here avail our- 

 selves of the opportunity of explaining the figures that we 

 have now the pleasure of laying before our readers, by giving 

 a detailed explanation of them. 



The antennae (fig. 3 & 3*) are very singular in their con- 

 formation, and may be called auriculate; the process or style 

 inserted in the globose base has not been before noticed ; and 

 in the genus Melophagus it is still more extraordinary, being 

 4-cleft and arising out of an aperture in the globose portion of 

 the antenna, which is hollow. 



Fig. 4. shows a great portion of the underside of the head, 

 forming what I have called the mentum ; it conceals and pro- 

 tects the trophi when at rest, at which time the ovate base, 

 fig. 2 h, rests within the spot with a row of bristles immedi- 

 ately above the figure 4 ; the bristles at the anterior angles are 

 peculiar; the maxillae (d) are similar to those of the neigh- 

 bouring genera. 



Fig. 2. exhibits the trophi, takeh out, with the part attached 

 to the head, which from its elasticity and length enable the 

 insect to exsert them the whole length of the lip beyond the 

 mentum ; at the base arise 2 curved bristles, probably to regu- 

 late the direction of the tongue, &c. when in action. 



Fig. 1. g, c, b. are the trophi detached, better to show their 

 form. 



The wings from their disproportionate width cannot, we 

 conceive, enable the insect to fly, but may be useful in assist- 

 ing it, when accident has thrown it upon its back, to recover 

 its natural position. 



It must be confessed, that the poor House- Swallow, whose 

 nest and feathers are infested with this parasite, which (by 

 comparison) is a monster in size as well as in form, is by no 

 means to be envied ; and the exhaustion occasioned by supply- 

 ing nutrition must be very considerable where these insects 

 abound in an individual, as is often the case. 



C. Hmmdi7iis is I believe the only species that has yet 

 been discovered of the genus ; that inhabiting the Swift {Hi- 

 rundo Apus Linn.) being an Oxypterum. 



The plant is Draha voma (Common Whitlow-grass). 



