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Show 1905.] HEMIPTERA OF THE SUBFAMILY HALTIN'^E. 147 more or less " elongated body." Berg* has described two new genera from the southern parts of South America, Proczelicus and Lobepomis, which he says are allied to the genera Amaurochrous Stll and Oncocoris Mayr; but judging from the descriptions it seems very doubtful whether they belong here, the more so as Amaurochrous does not appertain to the Halyinse at all. Distant t has also described an African genus, Crollius, which he places near Platycoris, but as nothing is said in the description as to the presence or absence of the strigose ventral patches, its position is uncertain. It is said to have the " rostrum about reaching the anterior coxfe " ; if this be correct, it scarcely belongs to the Halyinse. Besides the seven genera referred to this group by Stal, there is one described genus which appertains to the same group, viz. Gommius Stal. Stal overlooked the striolated ventral patches of this genus and therefore incorrectly placed it among the Pentatominfe s. str., near Chalcocoris Dali. For this division of the Halyinse I propose the name Platycoraria; all its genera, except Mecidea, are Australian, two of them (Oncocoris and Caridophthalmus) extending to the Austro-Malayan region (New Britain, New Guinea, Timor, Flores, Ceram). As Stal + calls the strigose ventral patches of the Tetyraria " niacidce strididatorice," but only speaks of " vittce strigosce " in the Platycoraria, it is evident that he did not recognise their true nature in the latter division. A close examination of the ventral patches of the Platycoraria shows, however, that they are perfectly homologous to the strigose areas of the Tetyraria, As described by Handlirsch, the stridulatory organs of the Tetyraria are made up of two different parts-(l)the passive element, consisting of the strigose ventral patches ; and (2) the active element, consisting of a series of minute wart-shaped tubercles, bearing a subapical tooth or bristle and placed on the inner side of the tibiee. The ventral patches are straight and situate on each side of the median line of the fourth and fifth segments, sometimes extending to the third or sixth segment; they converge behind and the strite are arranged longitudinally, being nearly parallel to the axis of the body. When the insect bends the tibia against the femur and again stretches it, the spinous tubercles of the tibia pass across the strigose surface of the venter, thus enabling the insect, by rapidly repeating these movements, to produce an audible sound. In the Platycoraria both the active and the passive parts of the stridulatory organ show the same structure as in the Tetyraria, but the ventral patches are usually comma-shaped, a little elevated and placed near the base of the venter, beginning with a rather broad base at the anterior margin of the second segment and proceeding, gradually tapering and curved inwardly, to the posterior margin of the third (rarely second) segment, where they end not far from the median line. Tho * An. Soc. Cient. Arg. xxxii. pp. 234 & 236 (1891). f Ann. & Mag. Nat. Hist. (7) vii. p. 21 (1901). t Enum. Hem. iii. p. 3 (1873). 10* |