DELTOCHILUM. 37 



punctulatis, hie illic rugulosis. <$ major ; tibiae posticae apice intus lobulato-produetae, femoribus inter- 

 mediis infra carina elongata. 

 Long. 22-28 millim. rf $ . 



Hal. Mexico, Misantla, Vera Cruz (Edge), Santecomapan (Salle). 



This Mexican variety agrees with the North- American type-form in the outline of the 

 thorax in both sexes, the sides in both being rotundate-dilate in the middle, and not 

 sinuate either before or behind the dilatation. 



4. DeltochHum lobipes. (Tab. II. fig. 13, <? .) 



D. gibboso proxime affinis, sed differt thorace medio valde angulato-dilatato, antice et postice (praecipue in 

 maribus) sinnato. Cuprascenti -nigrum, subnitidum ; tborace minute et sparsius punctato, limbo groasius 

 annulato-punctato ; elytris subtiliter punctato-striatis, interstitiis annulato-punetulatis, medio convexis 

 ibique seriatim nitide granulatis. <5 major ; tibiae posticae apice intus incurvas et late lobatae lobo apiee 

 rotundato ; femoribus intermediis subtus carina brevissima. 



Xong. 22-30 millim. S $ . 



Hob. Mexico, Tehuantepec (Sumichrast), Tapachula (Hoge) ; Nicaragua, Chontales 

 (Belt). 



Less typical examples are in the collection from Jalapa and Tampico (H'dge), but 

 only a single male from each locality. They accord in the strongly angulate and 

 bisinuate sides of the thorax, but differ from the type-form in the elytral interstices 

 being scarcely perceptibly convex and almost destitute of shining granules*. 



The figure is taken from a well-developed male example from Tehuantepec. 



5. Deltochilum mexicanum. 



Deltochilum mexicanum, Burm. in D'Alton's Zeitschr. fur Zool. i. p. 135 \ 



Sab. Mexico \ Cordova (Salle), Jalapa, Misantla, Vera Cruz (Hbge) ; Costa Rica 

 (Salle, Van Patten), Irazu (Rogers) ; Panama, Volcan de Chiriqui (Champion). 



* It is interesting to find that the species of Deltochilum which represents the Forth- American D. gibbosum 

 in the Amazons region is more nearly allied to the North-American than to the Central -American form, the 

 shape of the thorax being very nearly that of D. gibbosum. The following is a description : — 



Deltochilum amazonicum. 



Obscure nigro-cupreum ; thorace medio angulato-dilatato, lateribus ante et post angulum subrectis, crebre 

 annulato-punctato, disco simpliciter punctulato ; elytris foveato-striatis, interstitiis subplanis, annulato- 

 punetulatis, medio seriatim nitido-granulatis. <$ major ; tibiae posticae apice intus curvatae, sublobato, lobo 

 apice lato obtuso. 

 Long. 22-28 millim. 6 $ . 



Hab. Amazons, Ega, Pebas. Some examples from Pebas have very conspicuous and elevated rows of 

 shining granules on the elytral interstices. 



The females of this species, as well as of D. lobipes and D. gibbosum, var. sublceve, vary like the males in 

 degree of development, and sometimes have rudimentary elytral bosses. All have rudiments of a tooth under- 

 neath the anterior tibiae, which are narrow and sharply bent, almost as in the males, and the deep fossa of the 

 metasternum is also present, but in a rudimentary state. The only constant sexual differences of outer 

 structure lie in the ventral segments and the apex of the hind tibiae : the former being consolidated in the 

 middle in the male, free in the female ; and the latter produced, with an apparently short spur, in the male, and 

 truncated, with a long spur, in the female. 



