1866.] MR. H. W. BATES ON FORMOSAN COLEOPTERA. '.U7 



mandibles (in well-developed males) is totally different, the apical 

 suberect tooth resembling that of other species found in China, such 

 as N. sinicus and N. ckcnnpioni." 



To this description I will add that the feebly developed males have 

 scarcely any trace of the erect tooth, and therefore do not much differ 

 from the same form in N. castanopterus ; the side of the head before 

 the eyes remains, however, always much more dilated laterally than 

 in N. castanopterus. The convexity of the elytra culminates at one- 

 third of their length, and then gradually slopes to the apex ; in N. 

 castanopterus the elytra are convex to about three-fourths of their 

 length, and then dip rather abruptly to the apex. 



The female resembles the male in colour and form ; but the sides 

 of the head are much more dilated exterior to the eyes, and angulated. 



iEGUS FORMOSA. 



y£go lsevicolli simillimus, differt tantum ( d ) elytris ad basin an- 

 ffuste et apud latera late crebre punctatis, interstitio tertio a 

 margine etiam multo latiore. 



This apparently common Formosan species is so closely similar to 

 JE. Icevicollis of China that it can scarcely be considered more than 

 an insular modification of it. In the punctuation of the elvtra it 

 is almost identical with JE. capitatus of Malacca and Borneo ; but 

 it differs much from that species in the shape of the thorax, position 

 of the mandibular teeth, and in other points, in which it agrees 

 exactly with JE. Icevicollis. 



NlGIDIUS PARRYI. 



Oblongus, niger, nitidus ,- capite quam thorax paulo angustiore, 

 lateribus ante ocidos rotundato-dilatato haud angulato, fronte 

 depressa sparsim minus grosse punctata ; mandibulis ( c? ) por- 

 rectis, apice recurvatis, supra ritgoso-pitnctatis absque dente 

 erecto, intus obtuse dentatis ; thorace angiitis anticis obtusis, 

 margine laterali antice incrassato, medio valde emarginato, an- 

 gulis posticis late rotundatis, supra Icevi, nitido, sulco dorsali 

 abbreviato rugoso, plaga parva utrinque laterali punctata : 

 elytris late punctato-sulcatis. 

 Long. (mand. excl.) Hi lin., mand. li lin. <$ . 

 A more elongated insect than the other two continental Asiatic 

 species (N. cornutus and A r . obesus), and differing from all the allied 

 species in entirely wanting the erect tooth or horn-shaped dorsal 

 apophysis of the mandibles. The sides of the head are rounded 

 before the eyes, and not produced into a point. The thorax has the 

 lateral margin excavated in the middle. The sulci of the elytra are 

 wide and deep, and have a chain of fovese, but are destitute of the 

 lines of fine punctures seen in N. Icevicollis ; the interstices are nar- 

 row, polished, and im punctate. 



NlGIDIUS FORMOSANUS. 



Oblongo-elongatus, niger; capite ante oculos difatafo, angulis 



