128 [June, 



BARYPITHES BUPLICATUS, n. sp., 

 AND NOTES ON OTHER BRITISH MEMBERS OF THE GENUS. 



BY J. H. KEYS, F.E.S. 



Plate II. 

 Whilst examining- my series of BarypUlies jjellucidus, Boh., a 

 short time ago, I noticed that it comprised two distinct forms. Being 

 unable to ascribe either of them to any other species, I referred the 

 matter to my friend, Mr. E. A. ISTewbery, who concurred with the 

 opinion that the two forms were distinct, but had been confused in 

 the extant descriptions. He then communicated the facts to Captain 

 Sainte- Claire Deville, who it appeared was well aware that two forms 

 of pellucidus were mixed in collections, and who had proposed to deal 

 with the question when a convenient opportunity arrived. He further 

 remarked, " From the materials you have sent me it results that the 

 Baryjiithes peJlucidns doubles itself in England absolutely in the same 

 way as in Trance. ... I have neither the time nor the desire to 

 attend to these insects at present, and shall be very glad if Mr. Keys 

 or yourself will describe the new species." 



Mr. Newl)ery referred the matter back to me, and, thus impelled, 

 I offer the following solution of the problem. 



The question which it is necessary first of all to answ^er satis- 

 factorily if possible is : to which of the insects must the name pellu- 

 cid^ls be conserved ? For convenience of reference, I propose to speak 

 of the form which I consider to be the true ;peJh(cidns, Boh., as No. 1, 

 and of the duplicate form as 'No. 2. 



In general aspect the two insects differ from each other very 

 much. No. 2 is conspicuously the smaller in size, averaging about 

 3 mm. in length ; it also is a more dunipy looking insect, with legs 

 distinctly stouter, and on that account seemingly shorter too. It is 

 reddish-yellow brown in colour, and paler than No. 1. No. 1, on the 

 contrary, varies in size from about 3 to 4 mm. ; its legs are thinner, and 

 accordingly look longer. In colour it is generally dark pitchy or 

 almost black, although lighter individuals (immatiu*e, perhaps) occur, 

 and are reddish-brown. The males of both forms are easily separable 

 from each other, as well as from their respective females. 



The females are not so readily distinguished, but the elytra of 

 No. 1 are, as a rule, more truncate at the base, with the humeral angles 

 consequently more distinct. In the large females of No. 1 the size and 

 flat interstices of the elytra are also distinctive points. In the females 

 of No. 2 the average smaller size, paler colour, and more distinct hairs 

 must also be considered. 



