12 Mr. Westwood's Observations on the Genus Derbe. 



parative paucity of the veins of the wings as compared with those of Plata, 

 Lystra, &c. ; 3rd, the unarmed posterior tibiae ; and 4th, the minute annular 

 form of the basal joint of the antennae, and the large size of the second joint. 

 I would have added to these the presence of ocelli, but we have seen that 

 these organs are apparently wanting in Thracia. Now we find these four cha- 

 racters equally strong in the genera Otiocerus and Anotia of Kirby, as well as 

 in some other insects which are described below, all of which I consequently 

 regard as subgenera of Derbe. 



Otiocerus. Kirb. (Cobax. Germar.) 

 appears indeed to be destitute of ocelli ; and the antennae, especially in the males, 

 are very anomalous, but in all other respects these insects are true species of 

 Derbe. Mr. Kirby having given no representation of the rostrum, I have added 

 a figure of the entire head of the female of O. Degeeri, Kirb., in which sex the 

 antennae are very short and bilobed (Tab. II. fig. 4 B). This species has the 

 anal angle of the fore-wings dilated into an angular projection (fig. 4 A), and 

 has been accordingly formed into a distinct genus by Dr. Burmeister under 

 the name of Hynnis rosea ; but it will be seen, on comparing the veining of 

 the wings of this species with that of O. Coquebertii, Kirb. (of which I have 

 also given an enlarged figure. Tab. II. fig. 5.), that the arrangement of the 

 veins is almost identical ; so that it will be necessary to suppress Dr. Bur- 

 meister 's genus Hynnis. 



The eyes in Otiocerus are emarginate, as they are also in Phenice, although 

 in the typical species of Derbe they are almost round. 



On comparing the wings with those of Derbe and Mysidia, it will be seen 

 that the postcostal vein here acquires a more important character than in those 

 subgenera, the median vein, although distinct, being nearer the posterior mar- 

 gin of the wing, and its apical branches occupying only the region of the anal 

 angle; whilst the apical branches of the postcostal vein {b*) extend through 

 the widest central part of the outer margin of the wing. The species of Otio- 

 cerus are from the southern parts of North America. 



Anotia. Kirb. 

 differs from Derbe in no material respect. Like Otiocerus, it has the eyes emar- 

 ginate, and the ocelli appear to be obsolete ; the antennae, having the second 



