142 GEO. H. HORN, M. D. 



feebly defined, short costse, iiuited by anastomosing Hues without distinct punc- 

 tures in the intervals; propleurfe opaque, sparsely granulate; prosternum 

 coarsely sparsely punctured with semi-erect hairs, the apex oval or subtruncate; 

 epipleurse well defined. Abdomen coarsely not densely punctate. Length .48 — 

 .66 inch. ; 12—17 mm. 



Ill some specimens received since the description of the unique, 

 the thoracic punctuation is somewhat irregular, so that there is a 

 tendency to form four smooth spaces, the two anterior spots being 

 closer than the posterior. 



Occurs in Grant County, N. Mex., and in Arizona. 



M. sulcipeiinis Lee, Journ. Acad, iv, 1858. p. 18; Horn, Trans. Amer. 

 Philos. Soc. xiv, 1870, p. 282, pi. xv, fig. 18. 



The specimen described by Dr. LeConte still remains unique. In 

 addition to the characters given by him the prosternum will be found 

 moderately wide and obtuse at tip and with the propleurte punctate. 

 The epipleurse are well defined ; met-episterna a little longer than 

 wide. Abdomen finely, evenly and not densely punctate. Length 

 .60 inch. ; 15 mm. 



Llano Estacado, Texas. 



M. robiista n. sp. — Oval, slightly oblong, dull black, with slight luteous 

 indumentum; labrnm with an acute, moderately deep notch. Head sparsely 

 obsoletely punctate, each puncture with a small yellow scale. Thorax one-half 

 wider than long, sides regularly arcuate, bind angles acute, prolonged backward 

 over the humeri, base a very little narrower than the middle of the thorax, disc 

 coarsely moderately closely and evenly punctate, each puncture with a small 

 scale. Elytra veiy little wider behind the humeri, disc vaguely bicostate, the 

 intervals with intricate elevations; prosternum very coarsely, sparsely punc- 

 tured, the apex broadly truncate and slightly impressed ; propleurse smooth ; 

 met-episterna sparsely punctate, longer than wide; epipleurse not well defined, 

 except near the base. Abdomen coarsely sparsely punctate, intervals scabrous. 

 Length .56 inch. ; 14 mm. 



This species resembles a Branckus more closely in form than the 

 preceding species ; it connects the latter very well with the next 

 species. 



It is to be regretted that this species was not found by me in time 

 to have it form a part of the Biologia series, but as the genus is here 

 considered collectively, it has been thought advisable to name it. 



Collected by Dr. E. W. Palmer, in Coahuila, Mex. 



The following synonymy has been observed : 



Usechus nudeatus Cas., Ann. N. Y. Acad. Sc. v, 1890, p. 176, is 

 scarcely a variety of lacerta. 



Asida angustula Cas., loc. cit. p. 370, is a male of muricatula. 



A. { Pelecyphorus) comiivens Lee, New Species, 1866, p. 110, is 

 the male of hifnrca Lee, as shown by additional specimens from 

 Lower California. 



Typical specimens of the above species have been examined. 



