Brillia

３－８　Ｂｒｉｌｌｉａ　ｇｒｏｕｐ　　（antenna with 4 segments・central tooth of mentum small＊）　　　　　　　　　　　　　　　　　　　
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　to Ｏｒｔｈｏｃｌａｄｉｉｎａｅ　ｇｒｏｕｐ

Brillia 　　　Neobrillia　　　Eurycnemus　　Ｅuryhapsis

	mentum*	antenna (4 segments)	SⅠ	SⅡ	other characteristics
*Brillia*	median teeth 3, center tooth small or absent. lateral teeth with 5pairs	segment 2 divited into 2 parts	plumose	thick, long simple	basal segment of antenna slightly curved.
*Neobrillia*	median teeth 3, center tooth small or absent lateral teeth with 5pairs. 4th tooth very small.	segment 2 divited into 2 parts	plumose	thick, long simple	both lateral sides of 4～10　abdominal segment with 1 pair of setal tufts
*Eurycnemus*	median tooth 1, .smaller than lateral teeth leteral teeth with 6 pairs	segment 3 short	thick, long simple	thick, long simple
*Euryhapsis*	median tooth 1, .smaller than lateral teeth lateral teeth with 6 pairs.. 5th tooth very small.	segment 3 not short	plumose	thick, long simple

Brillia

Body length around ５～８mm. They inhabit on the surface of pebbles in normal current. About 10 kinds larvae found in Japan .


Mentum : median teeth 3, center tooth small or absent Lateral teeth 5 pairs. Ventromental plate small.	Antenna 4 segments . Basal segment bent slightly. Segment 2 divited into 2 parts at lower part 1/3 . Antenna retio 1.2～1.5.
	・Mandible: lateral teeth (inner teeth) 4, 4th tooth fused to base ・ＳⅠ:plumose ＳⅡlong, simple. 　ＳⅢ. thin, simple. ・Pecten epipharyngis :3 trianglula scales. Premandible with 3 teeth. ・the hight of the procercus 1.5 times of the width , anal setae 8.

Neobrillia

Neobrillia resembles above Ｂｒｉｌｌｉａ　closely, but it is defferent from having setal tufts on abdominal segment as shown in the figure below. There are few kind of Neobrillia in Japan.


Two long median teeth and a small tooth between them. 5 pairs of lateral teeth, 4th. lateral tooth appressed to 5th.	mandible & antenna	both sides of abdominal segmen Ⅳ～Ⅹ.with 3 pairs pairs setal tufts
	・Antenna with 4 segments , segment 2 divited into 2parts with proximal part about 1/3 length of distal . ・Mandible with 4 inner teeth. Seta subdentalis long. ・ＳⅠplumose. ＳⅡlong, simple. ＳⅢ thin, simple. ・Labral lamella consisting of broad pectinate lobes. Pecten epipharyngis of 3 broad triangle lobes. Premandible broad with weakly bifid apex. ・The hight of the procercus 1.5～2 times of the width . anal setae 8. 　・Both sides of abdominal segmen Ⅳ～Ⅹ.with 2～3 pairs setal tufts.

Eurycnemus

Body length around ５～１０mm. Body color grayish green～ milky white. Head pale yellow. Eye spot 1 pair, small.
They were found in Kawakami river (Mie ) and Naruse river (Akita pref.), . Number of individuals are not many.


One median and 6 pairs of lateral teeth. Median tooth smaller than 1st lateral tooth. Ventromental plate absent.	ＳⅠ,ＳⅡ both thick and long.　 Pecten epipharyngis consisting of 3 broad triangular scales. Premandible broad ,bifid .
	・Head slightly flat. ・Antenna 4 segments , shorter than 1/10 of the head length., １/4 of mandible. ・Antenna ratio about 1.3.. ・4 inner teeth of mandible , seta subdentalis thin and long. ・Anal tubules 2 pairs ,egg shaped. ・Procercus short, anal setae 2 long setae and 2～3 short setae. number of setae different by a kind.

Euryhapsis

Body length around ５～８mm. Body grayish green. Head yellowish brown. Eye spot 1 pair.
They inhabit in nomal or slow current , sandy pebble bottom. Takahasi river (Okayama pref). Kizu river( Mie pref.)


Median tooth small, 1st lateral teeth elongate. Lateral teeth 6 pairs, 5th tooth apressed with 6 th tooth. Ventromental plate small, very short beard present.	Antenna with 4 segments, antenna ratio 1.0. Ring organ on basal 1/4 of segment 1. Blade longer than flagellum.
	・Mandible : inner teeth 4. seta subdentalis long. 　・ＳⅠ: plumose. ＳⅡ: thin, long.. ・Labral lamella curtain shaped., fringed with small serrated. ・ Pecten epipharyingis 3 triangular scales.・Premandible with 3 teeth.

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