of a Specimen of Dyticus Marginalis. 205 



form and structure. The left intermediate tarsus, on the other 

 hand, has the basal joints rather broader than the right opposite 

 foot, but the small cups on the underside are not so numerous as 

 in the right middle foot. The tibiae in both of the fore feet are 

 dilated at the base, but each is furnished with two spurs at the 

 tip, as in the female ; the ungues in both fore feet are of equal 

 size, and notched at the base within. The upper edge of the 

 middle tibiae is furnished with long ciliae, the under edge is also 

 very slightly ciliated ; the calcariae are of unequal size in the 

 middle feet, and the ungues are of equal size and toothed at the 

 base. The hind feet are of the normal form, with the upper and 

 under edges of the tibiae and tarsi ciliated. 



Tiius, in respect to the sexual distinctions exhibited by the legs, 

 we find the masculine structure to exist, although not in its full 

 state of development; this imperfection being more especially 

 noticeable on the right side, in which indeed the fore tarsus mani- 

 fests an approach to the female structure in the short spines on 

 the underside of the basal joints at the tips, and the removal of 

 the little cups from the centre to the sides, so that if the sides 

 of the three basal joints of the fore tarsus on the right side were 

 removed we should have a tolerable representation of the female 

 anterior tarsus. I need scarcely say that this would not occur by 

 treating the ordinary male tarsus in the same manner. 



On examining the fore tibiae, as well as upper surface of the 

 thorax and elytra, we however find more evident proofs of the 

 assumption of the female characters. The thorax is indeed glossy, 

 but an examination of it under a lens shows that its anterior 

 margin is on each side finely punctured, whilst the left lateral 

 margin is also punctured ; punctures of the same size are also irre- 

 gularly scattered in little groups over other parts of the thorax. 



The right elytron is impressed close to the suture with four lon- 

 gitudinal furrows extending to the ordinary length of the furrows 

 of the female elytra ; the first nearest the suture is broken near 

 its posterior extremity by several raised parts ; the second has 

 one break near the tip ; the third is the shortest, and is interrupted 

 in the middle ; and the fourth is very irregular : the interstices 

 between these furrows are punctured as in the female. The re- 

 mainder of the right elytron is masculine. 



The left elytron has two short furrows near the suture ; that 

 next the suture is very short and is several times interrupted, and 

 the second, which is longer, has two long interrupted spaces ; near 

 the lateral margin there also exists a deeper furrow much inter- 

 rupted. 



VOL. III. Q, 



