336 MK. G. BOWDLEE BUCKTON ON UNDESCEIBED OE 



suprahvimerals and two wide yellow fasciae across the dorsum, leaving the apex black. 

 The tegmina are dense and do not readily show the neuration. 



Hab. Central America. Size 7x4 millimetres. 



Musee de Madrid. 



Perhaps this insect might be included in the original genus Ceiitrotm ; yet it differs 

 from Linnaeus's typical Centrotus cornutus, which has been retained for reasons set 

 forth in my 'Monograph of the Membracidae,' p. 245. 



There is no waste in the products of animal life, and it is a fact familiar to all 

 observers that the effete excretion of one animal is often the food for another lower in the 

 biological scale. The swefft secretions from many Homoptera are much sought for by 

 nuts and by the members of some insect families separate from them both in habit and 

 classification. Thus we have Aphidae, CercopidiB, Fulgoridse, and Membracidae all laid 

 under contribution for the pleasure or nourishment of different orders of insects. AYliilst 

 in the Aphidae we find at least two discharging orifices or nectaries for such excreta, 

 Mr. E. Green has shown that in Centrotus nectaris of Cevlon the larvae have but one 

 duct, wliich is capable of extension like the tube of some telescopes. 



The larvae of another species are common at the Cape of Good Hope, probably 

 belonging to the genus Oxyrhachls, which carry their single nectaiy erect from the apex 

 of the abdomen. They also are visited by ants. Although the winged insect has not yet 

 l)een ascertained, a figure of this curious lurva or pupa may be added to the singular 

 forms which represent the pupal and immature stages of the Membracidae. 



It may be remarked that these pupae are incapable of flight, yet they have the 

 rudiments of the tegmina much developed, and that tliey are very active in their move- 

 ments. They possess eyes and antennae. 



Future observation will show, indeed, whether they are pupae or only arrested imagoes. 



Pupa. (Plate 22. fig. 12.) 



Robust. Colour wholly black, except the eyes, w^hich are large, prominent, and 

 sordid ochreous. Metopidium continued into a single sharp and erect horn which 

 slopes nearly straightly to the apex of the abdomen, where it rises into an erect 

 coriaceous and conical nectary, wide at its base and tapering to its summit. This is 

 perforated and forms the nectary or duct for ejaculation, just as in Aphis. 



The wing-cases or rudimentary tegmina are short, pointed, and black, with traces 

 of an obscure neuration. Legs very stout, rather flat, witli coarse tarsi. Size 

 5x3 millimetres. 



These pupae are probably the immature forms of an Oxi/rhaehis which develops 

 .simultaneously in the month of January, at Wynberg, a suburb of Cape Town, Africa. 



The fact that these pupae have only a single horn above the metopidium, instead of the 

 double horn of Oxyi'hachis, need present no difficulty when we consider the extra- 

 ordinary shapes often assvimed by certain insect organs which are not really homologues, 

 though they may appear to be such. The legs of a larva need not be necessarily those 

 of the corresponding imago whicli emerges from it. 



