76 GEO. H. HORN, M. D. 



A. socialis Horn. — Moderately elongate and parallel, feebly convex, rufo- 

 ferruginous or pale castaneous, shining. Antennae pale rufotestaceous. Head 

 short and broad, less convex than usual, dissimilarly sculptured in the sexes. 

 Clypeus broadly truncate and feebly emarginate, the sides arcuate, gensB very 

 prominent, but obtuse. Thorax nearly twice as wide as long % or less than that 

 9 , the sides arcuate, more feebly in 9 > hind augles very broadly rounded, the 

 sides and base forming a continuous line, base arcuate, the marginal line very 

 tine; disc moderately convex, dissimilarly sculptured in the sexes. Elytra as 

 wide at base as the thorax, humeri not dentate, striae deep, crenately punctate'^ 

 or less punctate 9 t intervals moderately convex, smooth. Mesosternum opaque, 

 densely punctate, not carinate between the coxse. Metasternum smooth. Ab- 

 domen with extremely few tine punctures, the segments crenate in front. Pos- 

 terior femora sparsely punctate, without marginal line % , or with feeble nearly 

 entire line 9 • Length .18-.20 inch ; 4.5-5 mm. 



Male. — Head broader and shorter, the genge arising rectangularly from the 

 head, surface sparsely and tinely punctate. Thorax nearly twice as wide as long, 

 the disc moderately convex, irregularly sparsely punctate, the punctures fewer 

 in front and less numerous near the sides. Anterior tibiae slender, bidentate* 

 externally, the apical spur incurved at tip. 



i^ejnaZe. — Head less transverse, moderately closely punctate, rugose in front 

 and at the sides, more distinctly emarginate at middle. Thorax less transverse 

 than in the % , the sides less arcuate, disc rather more convex, the punctures 

 coarser, more numerous, gradually finer anteriorly. Anterior tibiae normal in 

 form, tridentate externally, not crenate above, the terminal spur shorter and 

 simple. 



At the time of the first description of this species I had seen but 

 two females, which were sent by Salle to Dr. LeConte under the 

 manuscript name which I adopted, hence ray failure to recognize the 

 remarkable sexual differences afterwards indicated by Harold (Berl. 

 Zeitschr. 1874, p. 174). 



The species is otherwise so remarkable that I translate Harold's 

 remarks : " The posterior tibiae are without transverse ridges, a char- 

 acter which forbids its association with Aphodius, and allies it with 

 Atcenhis, Saprosites and Euparia. On the middle tibia there is, how- 

 ever, a transverse ridge, in which it resembles Saprosites. Saprosites 

 is characterized by the relatively short tarsi and the denticulate 

 middle tibise, characters to which the graceful and slender tibiae and 

 tarsi of A. socialis are foreign. If, therefore, one does not desire to 

 create a new genus for every aberrant form our choice of position must 

 be between Ata;nius and Eujmria. The short and transverse head 

 with the prominent gense suggest Eiqmria ; the posterior tibi?e 



■■■" Apropos of this character Harold remarks that but one Aphodiide is known 

 to him with this character Aph. fuJviventris. Among our Aphodius several have 

 the upper tooth either entirely or partially obliterated, as will be seen by refer- 

 ence to the preceding pages. 



