192 NEW GENERA AND SPECIES 



genera ; here the maxillae are exactly formed as in Centroglossa ; 

 the lower parts of the mouth are also evidently similar, 

 although, from the labium being retracted, Mr. Haliday was 

 compelled to pass it with a mark of doubt, adding, that the 

 palpi are ' represented by two parallel spines, so long as to 

 pass beyond the extremity of the mandibles,' and which were 

 the only parts of the labium which he had seen. The Oxy- 

 telideous form of the body in Diglossa, and especially the struc- 

 ture of the tarsi, separate it widely from Centroglossa." 



To the above observations of Mr. Westwood, I must add, 

 that the labium in Centroglossa is not only retractile, but also 

 capable of considerable expansion ; for, in some specimens 

 which I have dissected, the anterior margin of that organ, 

 (which, as may be seen in Fig. b. 2, usually falls into a 

 deep notch, forming the two lobes,) was nearly straight; and 

 in this case the long filaments proceed more or less from the 

 opposite corners of the mouth, extending nearly their whole 

 length beyond it, and divaricating considerably. 



Mr. Westwood then goes on to say, " In addition to this 

 genus, Dr. Erichson has just published the characters of 

 several new genera of ' Aleocharini ,'' closely allied to these ; 

 and, as his work is as yet in very few hands, it may be service- 

 able to give his short Latin characters of these genera, as they 

 will, in all probability, occur in our own country. 



" SiLUSA. — Maxillce malls insequalibus, interiore elongata, corned, 

 apice uncinnata, intus subserrat^ : ligula elongata, angustata, 

 Integra paraglossis nuUis : palpi lahiales exarticulati, setacei : 

 tarsi antici 4-postici 5-articulati, oranes articulis primis aequa- 

 libus. 



One species. — S. rubiginosa. (If line long.) 



" Pronom^a. — Maxillce malis jequalibus, elongatis, interiore 

 cornea, apice uncinnata : ligula bifida, minuta, sub mento 

 occulta, paraglossae nullse : palpi lahiales exarticulati, setacei : 

 tarsi antici 4-, postici 5-articulati, postici articulo primo elon- 

 gato. 



One species. — P. rostrata. (Length Ih Hn.) 



" Gymnusa, (Karsten.) — Maxillce malis aequalibus, elongatis, inte- 

 riore cornea, apice uncinnata, intus serrata: ligula bifida, 

 laciniis porrectis, elongatis, setaceis, palpis aequalibus, para- 

 glossae null* : palpi lahiales setacei, 3-articulati, articulo 1"°. 



