MUSEUM OF COMPARATIVE ZOOLOGY. 17 



In Nos. 1, 2, 3, and 6, punctata agrees better with hyalina than with discoi- 

 dalis; better with discoidalis than with hyalina in Nos. 4, 5, 7, and 8. In Nus. 

 1, 4, 7, and 8, discoidalis agrees better with punctata than with hyalina; better 

 with hyalina than with punctata in No. 3. In Nos. 1, 2, 3, and 6, hyalina agrees 

 better with punctata than with discoidalis; better with discoidalis than with 

 punctata in Nos. 5 and 7. On the whole, punctata (Hood) stands between the 

 other two, showing slightly closer alhuity with discoidalis (Chatham) than 

 with hyalina (Tower), 



It is impossible, from Walker's meagre and unimportant description, to 

 determine whether the race found on Charles Island (if indeed his specimens 

 came from there) agrees with either of tliese three or not. In size it agrees 

 perfectly with S. I. hyalina, Init his " antenno3 piceous, tawny toward the 

 base," would seem to exclude it, and even more his description of the tegmina 

 as " towards the base nearly wholly black," while his " front thinly punc- 

 tured " points rather to S. I. discoidalis. It is more probable that Charles Island 

 harbors a peculiar race. 



This species, though a true Schistocerca, departs from the typical structure in 

 the direction of Osmilia by the narrow space between the eyes, which is con- 

 siderably less than the width of the upper narrowed part of the frontal costa. 

 The prosternal spine is stout, cylindrical, narrowing only at the subacuminate 

 tip. It has no sort of special relation to the Caloptenoid series, as stated by 

 Walker (loc. cit., V., Suppl., 63). 



Mr. A. Agassiz states that this species is confined to the lower levels of the 

 islands it inhabits, and is not found inland, where S. melanocera has its station. 

 Wolf made a similar observation. 



HALMENUS (aWoixai), gen. nov. 



Having the aspect of Pezotettix. Head pretty large, but appressed, higher 

 and broader than the pronotum, the space between the eyes of the same breadth 

 as the summit of the frontal costa ; fastigium of vertex in front of eyes rhom- 

 boidal, plane, slightly declivent, rounded on the front lateral margins so as to 

 join imperceptibly with tlie frontal costa, which is of subequal breadth, sulcate 

 at and just below the ocellus, a little contracted at sunnnit. Eyes subprora- 

 inent, regularly ovate, half as long again as the genas below them. Antennae 

 linear, subdepressed, much longer than head and pronotum together. Pronotum 

 compressed, the dorsal area transversely gently convex, melting gradually with 

 no carina into the lateral lobes; metazona faintly carinate, posteriorly obtusan- 

 gulate and much shorter than the prozona, the latter cut by two distinct sulci, 

 one scarcely in front of, tlie other a little behind, the middle ; lateral lobes 

 longer than high, both angles obtuse, the lower margin truncate a little 

 oblicj^uely in front ; no humeral sinus. Prosternal spine erect, conical, bluntly 

 pointed. Mesosternal lolies distant but nearer apically than at Ijase, with 

 straight margins ; nietasternal lobes a])proxiniate in the male, almost as distant 

 as the mesosternal lobes in the female. Tegmina abbreviated, sublanceolate, 



VOL. XXV. — NO. 1. 2 



