336 On Aquatic Carnivorous Coleoptera or Di/tiscidce. 



1. 18.— Genus QUEDA. 



Coxal incision shorter in the longitudinal than in the transverse direction : only the 

 fringes of the labrura visible; length G m.m. A single South American species. 



222. Queda compressa, n. sp — Picea, nitida, convexa, lata, posterius angustata, 

 et sat acuminata, elytrorum humeris rufis, antennis pedibusque rufo-testaceis ; dense 

 sat furtiter punctata. Long. 5^ m.m., lat. 3^ m.m. 



Mas, antennis articulis 3-5, ceteris longioribus et latioribus. 



Fern., antenni.s articulis 3-5 ceteris longioribus haud latioribus. 



Of a compact and peculiar form, very broad in front and acuminate behind. 

 Clypeus distinctly margined. Head finely and closely punctured. Thorax closely 

 and rather finely punctured, the punctuation extending quite to the sides. Elytra 

 closely, distinctly and evenly, but not coarsely punctured. Under surface distinctly 

 punctured, the punctures on the hind coxse coarser than elsewhere, those on the 

 ventral segments fine but numerous. A specimen in Bonvouloir's collection, labelled 

 " fulvipes Reiche Columbia," is possibly a distinct species, being entirely black, and 

 slightly longer. 



Brazil, (Santa Rita, August and Sept. 1850, R. F. Sablberg). 25. 



II. 7. — Group BiDESsiNi. 



The posterior border of the hind coxa? is completely soldered to the first ventral 

 segment. The hind coxal cavities are separated and not j^rotected by the adpressed 

 coxal processes. 



Tlie soldering of the hind coxa to the ventral segment is peculiar to these 

 insects, and occurs in no otlier Coleoptera. Except for this the other characters of 

 the group are much the same as in the Hyphydrini. 



{ On the iindersurface of head \ IIETEEIl YDRUS, (vide p. 

 tlie labrum is exserted. j" 337). 



Prosternal pro- 

 cess attaining - 

 the metaster- 

 num. 



Middle coxoe conspicu- 

 ously separated, pro- 

 sternal process broad 

 and short with obtuse 

 hind margin. 



^Middle coxm more ap- "| 

 proximate, prosternal | 

 process rhomboidal. ■ 

 with acute termin- 

 ation. 



ProsternalproccEsoblong. - 



Only the anterior border 

 and fringes of labrum 

 visibly exserted on under- 

 side of the head. 



PACHYDRUS, {vide p. 338). 



Prosternal pro- 

 cess notreach 

 ing to the me- f 

 tasternum. J 



_ \ DESMOPA CURIA, (vide p. 



j 340.) 



Coxal lines longer than pro- 1 j>jj)ESSUS, (vide p. 344.) 

 sternal process. J ; v r / 



Coxal lines shorter than the ) IIUXELnTDRUS, {vide p. 



prosternal process. 



3G9). 



) TYXDALLHTDRUS, {vide 

 / p. 370.) 



