1873.] 437 [Horn. 



the body, surface with striae of coarse punctures at base, punctures re- 

 placed gradually toward apex by rounded tubercles. Body beneath finely 

 alutaceous and obsoletely sparsely punctate. Length .12 inch ; 3 mm. 



This species is totally unlike anything in our fauna, and bears consid- 

 erable resemblance to the figure of Mesoxenus Bewickianus, Woll., Trans. 

 Ent. Soc. Lond., n. s. VoL V., pi. 19, fig. 6. 



Occurs on the sea beach near San Francisco. Specimens have been 

 sent me by Messrs. Edwards and Behrens. 



Cossonus Clairv. 

 The species of Cossonus may be divided into three groups which may 

 have generic value : 



Rostrum dilated at tip. Body more or less depressed A. 



Rostrum not dilated at tip. 

 Body linear, strongly depressed. Scape of antennas barely at- 

 taining the eyes. Rostrum porrected B. 



Body convex. Scape of antennas impinging on the eyes when 



at rest C. 



A. 

 This group may be considered to represent the typical Cossonus. The 

 rostrum is always distinctly dilated at tip, the antennal scorbes deep and 

 the ridge forming their lower boundary always visible from the front. 

 The species all resemble each other very closely and are difficult to sepa- 

 rate : 



Thorax truncate at base. Antenna? post-median Bohemanni. 



Thorax bi-sinuate at base. Antennas median. 

 Thorax broader than long, sides arcuate, surface very un- 

 equally punctured platalea. 



Thorax longer than wide, sides very feebly arcuate or 

 straight. 

 Base of thorax with slight tuberosity opposite the scu- 

 tellum. 

 Basal portion of rostrum longer than the dilated por- 

 tion subareatus. 



Basal portion equal to the dilated portion. 



Thorax narrower than the elytra, with coarse dis- 

 tant punctures, elytral punctures coarse. 



Thorax sub-depressed without concavity piniphilus. 



Thorax longitudinally convex, median line slightly 



concave behind concinnus. 



Thorax as wide as the elytra, punctures coarse but 

 not distant, elytral punctures finer, serrate. 



Color black, striae deeper and broader at base crenatus. 



Color piceous, striae scarcely deeper and broader 



at base corticola. 



Thorax with median line at base sub-cariniform. 

 Basal portion of rostrum scarcely equal to the apical, impressifrons. 



