12 The Rev. F. W. Hope's Descriptio7is 



Mandibulce validae, corneae, externe convexse., apice subacutse, in- 

 terne dentibus binis obtusis armatse. 

 Maxilla: lobo interne acuto, falciformi, ciliis rigidis interne armato ; 



lobo externo palpiformi, 2-articulato. 

 Palpi maxillares breves, 4-articulati ; articulis tribus prioribus sequa- 



libus ; ultimo ovato, truncato. 

 Mentum magnum, corneum, valde emarginatum ; dente medio obtuso. 

 Palpi labiales 3-articulati, articulo Imo minimo, 2do paullo majori, 



Stioque maximo truncato. 

 Corpus parvum, oblongum, antice posticeque rotundatum. 

 Thorax conicus, antice abrupte truncatus, parte postica latitudinem 



elytrorum a?quante ; ad latera valde deiiexus. 

 Prosternuin acutum, inter pedes anticos protensum. 

 Pedes breves ; femoribus ovato -dilatatis, tibiarum basin fossula re- 



cipientibus. 

 Tarsi simplices, 5-articulati, longitudine tibias sequantes. Ungues 



recti. 



Adelotopus Gyrinoides. Plate I. fig. 1. 



Ater, nitidus ; marginibus tlioracis pedibusque piceis. 

 Long. corp. lin. 2-^, lat. lin. 1. 

 In museo Dom. Hope. 

 Habitat in Nova Hollandia. 



Caput atrum. Thorax concolor, marginibus lateralibus parum re- 

 flexis piceis. Elytra marginata, abrupte truncata, sparsim punc- 

 tulata ; punctis, sub lente, parum distinctis . Corjiu s infra nigrum, 

 nitidum ; segmentis abdominis postice, pedibusque piceis. 



This singular insect vi'as sent to me from the Swan River settle- 

 ment in New Holland. It seems to unite in itself the characters of 

 several families. From the tarsi it is referrible to the Pentamera, 

 whilst its general appearance and clavate antennae place it among 

 the Necrophaga. By the subcontractile legs, (for the bent tibiae are 

 not entirely concealed within the femora,) it is allied to Byrrhidce, 

 but the leading character afforded by the maxillae evinces a near 

 affinity with the Entomophaga, amongst which the Gyrinidce must 

 be considered the nearest in proximity, Gyrinus bicolor, Fab., some- 

 what approaching this insect in form. 



Family Byrrhid^. 



MicrochjETEs*, Hope. (Genus novum.) 



Antenna 11 -articulatae, clavatae, articulo Imo magno, 2do paullo mi- 



* fiiK^oi parvus, et ;t;a/T)j capil/us. 



