88 INSECTA MADERENSIA. 



Readily kno^\Ti by its small size and ovate form, by its pallid hue, and by the 

 abbreviated black lines A^ith which the apical portion of its elytra are decorated ; 

 — but which are somewhat shorter and less distinct in the single Madeiran 

 specimen which has hitherto come beneath my notice than in the ordinary type. 

 It is to M. Uousset tliat we are indebted for the admission of tliis species into our 

 fauna, a unique example (Avliich is just perceptibly narrower than is usually the 

 case with its more northern representatives) having been lately discovered by him 

 in the immediate vicinity of Funchal. It is an abundant insect throughout the 

 whole of Em'ope and in the north of Africa, — being recorded in Egypt, Algeria, 

 and Barbary. 



Fain. 3. GYRINID^. 



Genus 28. GYRINUS. 

 Linnaeus, S_i/st. JS'af. ii. 567 (1767). 



Corpus parvum, ovatum : ocu/is quatuor : prothorace basi in medio producto : alls amplis. Antenna 

 lO-articulatse, brevissimse, articulo primo minuto, secundo maximo globoso extus in lobum pro- 

 ducto, reliquis brevissimis inter se arete applicatis, clavam fusiformem eflBcientibus. Labrinn 

 transversum, antice levitcr emarginatum. Mandihula breves, apice emarginato-dentatne. Maxilla 

 bilobse : lubo extei-no angusto subulate, exarticulato : interno acuto incurvo, ad apiceni uncinato, 

 intus valde ciliato. Palpi breves, articulo ultimo in maxillaribus magno ovato, in labialibus 

 graciliore. Mentuni transversum, antice profunde emarginatum. Ligula brcvis lata, apice 

 truncata. Pedes posteriores uatatorii, breves compressi ; postici elongati : tarsis postcrioribus 

 articulis primo, secundo et tertio intus valde productis, ultimo minutissimo. 



The Linnsean genus Gi/riuiis presents such remarkal)le featm-es in the struc- 

 tiu-e of its tarsi, antennae and mouth, that it is hardly necessary to point out its 

 ilistinctions from any of the ncighbom'ing forms. The species are indeed too well 

 known, from theu' habits, to require comment : tlicir small, brilliant l)odies so 

 constantly to be seen on the sm-faces of the stUl pools, ditches, and quiet waters of 

 nearly every country, — weaving cu'cles, and clustering, in the sun, — can scarcely 

 have failed to have attracted the attention of tlie most casual observers. I am 

 doul)tfid whether the group is truly indigenous to these islands, not having myself 

 succeeded in detecting it, and the only representative which I have hitherto seen 

 being an example of the common G. natator, given to me by the Eev. R. T. Lowe 

 from the collection of the late Dr. Heinecken, but unaccompanied by the details of 

 its capture. 



70. Gyrinus natator. 

 G. ovatus subviridesccnti-nigcr nitidus, elytris striato-punctatis, prothoracis elytrorumque marginibus 



inflc.xis, pectore, ano, pedibusque rufo-testaceis. 

 Long. Corp. lin, 3. 



