1902.] SPIDERS FROM BORNEO AXD SINGAPORE. 241 



The general colour of the beetle is reddish ochreous, the prothorax 

 is clothed with a fine golden pubescence ; the prominent black 

 eyes, the somewhat flattened antennae, and long hind legs closely 

 correspond with the same organs of the Salius ; further, the 

 elytra, though not shortened, are much reduced in width, rapidly 

 narrowing from a breadth of 3'5 mm. at the base to 1 mm. at the 

 apex, so that the clear golden wings are very imperfectly hidden 

 and add not a little to the general wasp-like appearance. When 

 seized, this beetle curved down its abdomen in the most charac- 

 teristic wasp-like manner, and it was only with the greatest 

 reluctance and most careful precautions that my Dyak collectors, 

 to whom I pointed out the insect, captured it. As in the Ohereas, 

 no representatation has here been made in dorsal view of the 

 wasp-waist of the model, and for the same reason, namely, that 

 this is hidden, when the Salius settles, by its wings, and it is 

 only at such periods of rest that the full effect of the deceptive 

 resemblance can be appreciated ; that part, however, of the first 

 abdominal segment of the Notliopeus which is visible from the side 

 and below is clothed with a golden-gi-ey pubescence, which produces 

 the same effect as in the Obereas. 



It is possible that this species of Nothopeus is itself distasteful 

 like the mimicked genera Chloridolimi and Leontium (see later), 

 but I could distinguish no pungent odour like that emitted by 

 those genera, and I am inclined to think that its mimetic resem- 

 blance is its sole defence. 



I have lately become acquainted with a mimetic species 

 belonging to the B^lhis^.Yin\J JSFecydalince (Plate XIX. fig. 12, no. 16 

 in Table I.), described in Appendix II. as Psebena brevipennis, and 

 I therefore add some details of its habits and of the mode in which 

 the mimetic I'esemblance is attained. The species in question 

 mimics with a remarkable degree of accuracy one of the common 

 red-and-black Braconidae : these Hymenoptera, as already shown, 

 serve as models to a considerable number of sj)ecies of Oberea, 

 but in none of these latter is a Hymienopterous appearance so 

 admirably borne as in this, a member of a subfamily for the most 

 part characterized by a reduction of the elytra. The head and 

 prothorax are of an Indian red, the wings are purplish-black, the 

 two anterior pairs of legs are testaceous, the long slender posterior 

 pair black with the bases of the femora white ; the body is so 

 slender that the necessity of producing a wasp-waisted effect by 

 means of lateral white patches, as in some of the above-noted Obereas, 

 can be dispensed with. 



Most gf the life of this beetle, as in all Longicorns with reduced 

 elytra, is spent on the wing, when it is simj^ly indistinguishable 

 from its model ; when it comes to rest the resemblance is still 

 remarkably exact, and its quick restless movements and habit of 

 flickering the antennae in all directions are very Bracon-like. 

 No specimen at all resembling this remarkable species has hitherto 

 existed in the British Museum. 



Of the NecydalincB,, one species Epania simgaporensw (Plate 

 Prog. Zool. Soc— 1902, Yol. II. No. XVI. 16 



