254 BULLETIN 63, UNITED STATES NATIONAL MUSEUM. 



MeasureTnents. — Males: Length, 18.5-19.5 mm.; width, 7-7.8 mm. 

 Females: Length, 17.8 mm.; width, 7.2 mm. 



Forma elongata. — Comparatively large and distinctly elongate. 

 Two subforms can be recognized. 



Forma elongata laevis. — Aliitaceous ; antennae reaching to or beyond 

 the prothoracic base; elytra very finely and obsoletely 2:)unctate, legs 

 long, posterior tibise verj^ slender, and more or less arcuate in basal 

 half in the males. 



Measurements. — Males: Length, 19.5-29 mm.; width, 6.5-9 mm. 

 Females: Length, 24-29.5 mm.; width, 8.5-10.5 mm. 



Forma elongata punctata. — This is more or less sliining; antenna? 

 reaching to or be3^ond the prothoracic base; eWtra with the serial 

 punctures rather coarse and more or less impressed, the interstitial 

 punctures are small but distinct. Legs moderately long and rather 

 stout, posterior tibia' in the males stout and straight. 



Measurements. — Males: Length, 24-28.5 mm.; width, 7.5-9.5 mm. 

 Females: Length, 27.5 mm.; width, 10.5 mm. 



Forma typica. — Glabrous, very bright and shining ; thorax with the 

 sides strongly sinuate in front of the basal angles; legs moderate (see 

 salient type-characters) . 



Variations. — Examples of the typical form taken about San Fran- 

 cisco Bay and in the series before me frequently present the follow- 

 ing variations: Antenna? rather stout or slender, varying in length 

 irrespective of sex, rarely two of dift'erent lengths in the same in- 

 dividual; the relative length of joints differs in individuals of the 

 same sex; outer four joints ma}^ be noticeably dilated, subclavate, 

 again not in the least dilated ; anterior pronotal angles simply acute 

 and not prominent to acuminately produced and very strongly 

 everted, the pronotum itself may be subquadrate; eWtra sometimes 

 widest behind the middle. 



Measurem^ents. — Males: Length, 22-28.5 mm.; width, (5.5-8.5 mm. 

 Females: Length, 23-28 mm.; width, 8.5-9.5 mm. 



Forma prominens Casey. — Form somewhat as in dentipes^ convex, 

 smooth, and alutaceous throughout. 



Head moderate, finely, sparsely punctate, more densely so toward 

 the sides of the epistoma. Antennm short and very robust, much 

 shorter than the head and prothorax, third joint about twice as long 

 as wide and equal in length to the next tAvo. 



Prothorax about one-sixth wider than long; disc rather strongly 

 convex throughout, finely and sparsely punctate, strongly aluta- 

 ceous, the side margins very minutely beaded ; apex broadly arcuate, 

 sinuate laterally, and subequal to the base ; skies broadly arcuate an- 

 teriorly, rather strongly convergent in basal half, and strongly sinu- 

 ate near the basal angles; hase broadly, evenly, very feebly arcuate; 



