Pelohiiis.] ADEPiiAOA. 159 



nous, (lull ; head fnu'ly puurtnrcil, free, with a hlack pateli on cither 

 side touchinff eyes, wliich are hirge and prominent ; thorax very narnjw, 

 anterior and posterior margins broadly black, finely rugose at sides, 

 middle of disc finely punctured, anterior margin with a thick fringe of 

 Avhitish hairs, anterior angles somewhat prominent ; elytra with a very 

 large common black spot covering the gi-eater part except margins and- 

 base, rugosely punctured, witli traces of large strife ; anterior tibite 

 armed with two long parallel spurs ; male with anterior and intermediate 

 tibise dilated, and clotlied underneath with thick pubescence ; breast 

 black, abdomen ferruginous except the two penultimate segments and 

 part of the last which are black. L. 8|-10 mm. 



Ponds and ditches ; local, but common in some districts ; it is widely distributed 

 and common in the Loiithm district, and has been recorded as plentiful in autumn at 

 times in stafjiiaut waters near Swansea, but it is a soutliern insect, and the iiorthcru 

 records are few and doubtful ; it has occurred once at Itepton, is doubtful as a York- 

 shire species, and the one reconl from Xorthumberlaud, "once near Newcastle, by Mr. 

 Hewitson," is especiady commented on by Mr. Hold as probably erroneous, us it has 

 never since been met with: it has not been taken iu Scjtlaud. 



DYTISCIDJE. 



The following are tlie chief characteristics of this family : — Antennae 

 eleven-jointed, glabrous and shining, entirely destitute of setaj or 

 pubescence, inserted very close to the eye, and quite close to the upper 

 portion of the base of the mandible ; maxillae with two lobes, the inner 

 curved at extremity and acuminate, the outer palpiform, divided into 

 two pieces by a transverse suture (in Amj^hizua it is entire); hind coxae 

 very large, soldered with, and appearing part of the metasternum, reach- 

 ing the margin of the elytra when closed ; posterior legs modified for 

 swimming by the tibiae and tarsi being furnislied with swimming hairs, 

 and being broadened and llattened ; posterior tarsi always five-jointed ; 

 the anterior and middle ones either four- or five-jointeil ; according to Dr. 

 Sharp the family contains about twelve hundred species, which w^e may 

 divide into two series as follows : — 



Jlctathoracic cpisternum not reaching the middle coxal 



cavity Drxrsci i-i£A(;\ri:\TATr. 



Metathoracic cpisternum reaching the middle coxal 



cavity DvLisui comi'licati. 



DYTISCI FP.AG.MENTATI. 



Metatlioracic episterna widely separated from the middle 

 coxa- ; hind coxa; extending furthest forward in miildle 

 of body (longitudinally) Notekina. 



Jletathoracic episterna nearly reaching the middle cox;u ; 



liin<l coxa; extending furthest forward towards sides . Laccoi'HI i-i N \. 



NOTERINA. 



Of this tribe we only possess the single gt^ms lYndrus, whicb is dis- 

 tingtiished by its convex sliape, more or less incra-ssale anteunie, and sub- 

 acumiiiale apex of elytra. 



