80 [April, 



to make out ; the distal se^me-nt lias a deep cleft, wherein are inserted two stout 

 claws and a bristle, as in Halohates, but the delicate leaf-like appendage beneath the 

 foot (fig. 3) is uni-epresented in any genus of the family known to me. The tarsus 

 of the third pair is very similar in form, only more elongate (fig. 6), and carries 

 coi'responding appendages, the bristle being clubbed. The hind legs are compara- 

 tively short ; the femur bears three pronunent spines distally, ■while the tibia is 

 ratlier strongly spinose throughout its length. The legs of the middle pair are 

 provided only with hairs and bristles ; in these legs the first tarsal segment is 

 longer than the second, which is cleft for the greater part of its length Within the 

 cleft are borne two claws, one of which, scimitar-shaped and ending in a sharp point, 

 projects from the cleft, while the other, upturned and quadrifid at its extremity, lies 

 in the cleft (figs. 4, 5). The bristles of the other feet seem to be represented by the 

 set of branched ciliated hairs. The individual hairs spring at excessively close 

 intervals from a common stem (figs. 5, 13), and each- bears more than a hundred fine 

 cilia. Apparently the whole apparatus can be withdrawn within the cleft, or ex- 

 panded to form a wheel-like disc (fig. 5). It is to be hoped that the use of this 

 unique and wonderful organ in tlie living insect may be studied by Mr. Duerden and 

 his fellow naturalists in Jamaica. 



The smallest larva before me measures 1'5 mm. in length (fig. 11). The tarsi 

 liave but one segment (fig. 12), but the cleft and ciliated hairs of those of the middle 

 pair hardly differ from the same structures in the adult. The body of the larva is 

 pale and soft, the chitinous tergites of the various segments appearing as paired 

 plates, with a median space between the two plates of each pair (fig. 11). In a 

 somewhat older larva than that figured the abdominal paired plates have united to 

 form single tergites, while the thoracic tergites remain divided down the middle 

 line. 



Trocliopus is differentiated from all allied genera* by the remarka- 

 ble structure of the feet of the second pair. It is also readily dis- 

 tinguished from the majority of the Halohatince by its elongate 

 abdomen. In this respect it seems to come nearest to the female of 

 Ii]ieumatohates,'\ in which the coxse of the hind legs are opposite the 

 fifth abdominal segment. In the male of the same genus these coxae 

 are pushed back opposite the hind extremity of the abdomen, as in 

 Halohates and its nearer allies {Metrocoris, Platygerris, &c.), while in 

 Hermatohates they project beyond the abdominal tip. From this 

 point of view, therefore, Trochopus presents a generalized type of 

 structure (indeed, its abdomen recalls that of Veliince), while in the 

 complexity of the appendages of the feet, it shows higher differentia- 

 tion than can be found in any other genus of the group. 



* See Lethierry and Severin, " Catalogue G^n^ral des H^miptferes," Tome iii, Berlin, 1896 

 (pp. 64 — 66). Also Bianchi, "Annuaire du Miisde Znoloyique de I' Acad. Imp. des Science.'^ de St. 

 Pdtersbourg, Tome i, 1896 (pp. 69—74), who gives a useful synopsis of all the genera of the sub- 

 family except my He7'matobates {type, H Haddonii from Torres Straits), which is easily characterized 

 by the extreme reduction of the abdomen, the immensely thickened front femora, and the 

 three-segmented tarsi on all the legs. 



t See Riley, Insect Life, vol. v, 1893, pp. 189—194. 



