REVISION OF LISTROCHELUS — SAYLOR 73 



half times their diameters on the disk, the punctures somewhat closer 

 at sides and along the frontal margin; basal margin entire; front 

 angles strongly rounded, hind angles obtuse, lateral margins entire 

 or faintly creniilate. Elj^tra finely, not densely, punctate, with striae 

 subobsolescent in basal half, sutural stria normal ; in a few specimens 

 there is a weakly indicated second stria. Pygidium strongly and 

 evenly convex, basal half or third pruinose, the apical portion highly 

 polished; disk sparsely and finely punctate, with very short erect 

 hairs. Abdomen flattened at middle and finely sparsely punctate; 

 sixth segment longer than the preceding, flattened nearly from side to 

 side, the flat area with fine scabrose punctures and very short, sparse, 

 and erect hairs. All claws strongly pectinate along a single margin, 

 without any larger intercalated teeth. First segment of hind tarsus 

 shorter than the second. Larger hind tibial spur usually one-fourth 

 longer than the first tarsal segment. 



Female. — Antennal club slightly shorter than the funicle; pygidium 

 convex and pruinose in basai half, apical half strongly convex and 

 highly polished, the center disk with a small, shallow foveate area; 

 abdomen highly polished at middle, subconvex in lateral view, the 

 apical segment moderately densely and finely punctate. All claws 

 pectinate along a single margin and each with a subapical, larger, in- 

 tercalated tooth. Otherwise similar to the male. 



Length. — 13-17 mm. Width. — 5.5-6.5 mm. 



Types. — The liolotype male is from ''5 miles S. of Miriiflores, Lower 

 California, collected VII-10-3S by Koss and Michelbacher"; the 

 allotype female is from "Miraflores, collected VlI-8-38" also by Ross 

 and Michelbacher; both types are in the California Academy of 

 Sciences. 



Paratypes: Lower California: 2 from Miraflores; 21 from 

 Triunfo, July 7, 1938 (Ross and Michelbacher), and from 6 miles 

 north of Triunfo, July 15, 1938; 2 from 5 miles west of San Bartola, 

 July 13, 1938 (Ross and Michelbacher). Designated paratypes are 

 in the collections of the California Academy of Sciences, the United 

 States National Museum (No. 53758), Messrs. Ross and Michel- 

 bacher, Mont Cazier, and in the Saylor collection. 



Remarks.— This interesting species at first glance resembles those 

 of the densicollis complex very closely, but the key characters will 

 readily separate the various species concerned. The male genitalia 

 of the present species are asymmetrical and tend toward the more 

 tubular type but are still somewhat similar to those of densicollis; in 

 the female miraflora the dorsal genital plate has been modified con- 

 siderably though still maintaining the basic type of the densicollis 

 group. 



