SCHISTOCERCA, SPHINGONOTUS AND HALMENUS 4I9 



derived from the Duncan race. But, the facts being as they are, the 

 seemingly less reasonable scheme outlined in the preceding paragraph 

 appears to be the more probable course of the formation of the varie- 

 ties as they at present exist on the different islands. 



DETAILED DESCRIPTIONS. 



SCHISTOCERCA MELANOCERA (Stal). 



(PI. XXVII, fig. I.) 



Acridiiim mehmocerum Stal, Eug. Resa. Ins. Orth., p. 326, 1861. 

 Schisiocerca melanocera Scudder, Bull. Mus. Comp. Zool., xxv, p. 11, 

 1893. 



From Charles Island. 



Description of a Typical Specimen. JPemale. — Ground color of 

 head black, markings yellow. Pattern of the latter is as follows : a 

 median stripe on the vertex, dilating slightly on the frontal lunule, and 

 then going downward as a narrow line on the frontal costa to between 

 the antennae ; below each antenna, on the floor of the subantennal 

 groove, a wide stripe extending to, and less distinctly for a short dis- 

 tance upon the clypeus, the two being connected by a fine line along 

 the lower border of the front ; a third stripe reaching from lower part 

 of anterior margin of eye downward along anterior border of gena 

 a little more than half way from eye to base of mandible ; a fourth 

 stripe arising from the lower part of posterior margin of eye and run- 

 ning downward along posterior border of gena to the inferior margin of 

 this sclerite. Antennae uniform dusky ; labrum with a bluish tinge ; 

 palpi yellowish, spotted with black ; compound eyes dark brown ; ocelli 

 yellow. Prothorax has prozona black with an irregular quadrateyel- 

 low spot on lateral angle of scutum. Metazona orange yellow with 

 an encroachment of black from prozona along anterior border ; poste- 

 rior marginal thickening black, with a narrow line of black mottling 

 just in front of it ; otherwise punctate with black especially on dorsal 

 aspect, yet the general orange yellow color contrasts strongly with the 

 black color of the prozona. Whole prothorax with a median dorsal 

 yellow carinal stripe continuous anteriorly with the median stripe of 

 vertex and extending posteriorly to caudal border of metazona. Pro- 

 sternum pale brownish, spine uniform with rest. Exposed lateral parts 

 of meso- and metathorax black, on each an elongate yellow area along 

 posterior border of the episternum ending below on a level with the 

 mesothoracic spiracle. Sterna of same segments dark brown. Color 

 in dry specimens a pale clay-color. Abdomen dusky, sides of terga 

 dark brown on the posterior part, forming a wide transverse band on 

 the anterior segments, a narrow band on the posterior segments. 



