242 Mr. G. R. Waterhouse's Descriptions of the 



sented by an indistinct prominence, which appears as if formed by 

 the converging and meeting together of the central pair of ridges. 

 The 6th and 7th abdominal segments in the female are simple. 

 By Erichson the segments in question are described as the 5th and 

 6th, but I agree with Dr. Kraatz in describing them as 6th and 

 7th. Usually the 1st, or basal segment, is hidden beneath the 

 elytra ; but in several specimens of Gyrophcena now before me, 

 owing to the body being unnaturally stretched out, it is per- 

 fectly visible. 



As regards the structure of the antennae, it may be remarked 

 that, as a rule, the intermediate joints (the 5th to 10th inclusive) 

 are transverse, dilated and of equal width, or very nearly so ; the 

 exceptions are found in G. affinis and G.pulchella, in which the cor- 

 responding joints are as long as broad, or some of them longer 

 than broad ; and in G. strictula, in which the antennae differ in 

 the succeeding joints becoming gradually stouter. The thorax 

 generally presents two parallel rows of punctures running from 

 the base to the apex, and near the centre : these are sometimes 

 placed in two longitudinal depressions ; the first puncture in each 

 row (or that nearest the base) is indistinct, the second is always 

 the largest, and one or two near the apex are usually distinct ; 

 the rest are more or less obsolete. In certain species (such as G. 

 manca and G. minima), where the thorax has scattered punctures 

 throughout, we still see the remains of the two dorsal rows repre- 

 sented by larger punctures, and especially the pair which cor- 

 respond with those of the 2nd pair of the dorsal series. In all 

 the species the thorax is margined at the sides and posteriorly — 

 a thin indented line following close to the margin in these parts. 

 In all the Gyrophcence the head and thorax are alutaceous, except- 

 ing in G. nana, where the peculiar sculpturing I am about to notice 

 is invisible, and the surface is unusually glossy. The alutaceous 

 appearance is caused by a sculpturing consisting of excessively 

 minute scratches ; the scratches are curved, and for the most part 

 inclose minute circular (or nearly circular) areas. It is seen most 

 distinctly in G. strictula; and is distinct under a compound mi- 

 croscope with a lens of an inch focus ; with the same power it is 

 not visible in G. nana, though with a stronger lens it may be in- 

 distinctly traced. In other parts of the body the alutaceous ap- 

 pearance is also perceptible, and mixed with it, in the abdomen , 

 minute punctures are visible, but so indistinctly as to furnish little 

 or no assistance in the discrimination of the species. 



