1905.] HEMIPTERA OF THE SUBFAMILY HALYIN.E. 147 



more or less "elongated body." Berg* lias described two new- 

 genera from the southern parts of South America, Proczelicus 

 and Lobejyomis, which he says are allied to the genera Amaurochrous 

 Stal and Oncocoris Mayr ; but judging from the desci'iptions it 

 seems veiy 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, CrolUus, 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 coxse " ; 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 gr"Oup, 

 viz. Commms Stal. Stal overlooked the striolated ventral patches 

 of this genus and therefore incorrectly placed it among the 

 Pentatominfe s. str., near Chalcocoris Dall, For this division of 

 the Halyinse I propose the name Platycoraria ; all its genera, 

 except Jfecidea, are Australian, two of them {Oncocoris and 

 Garidophthahnus) extending to the Austro-Malayan region (New 

 Britain, ISTew Guinea, Timor, Flores, Ceram). 



As Stal % calls the strigose ventral patches of the Tetyraria 

 " macidie strididatoince," 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 — ( 1) 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 tibiae. 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 

 stride are arranged longitvidinally, 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. The 



* An. Soc. Cient. Arg. xxxii. pp. 234 & 236 (1891). 

 t Aim. & Mag. Nat. Hist. (7) vii. p. 21 (1901). 

 X Eimm. Hem. iii. p. 3 (1873). 



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