236 CALIFORNIA ACADEMY OF SCIENCES. 



Zalobius Leo. Trans. Am. Ent. Soc. v, p. 49, March, 

 1874. 



This genus is introduced with the desire to give sketches 

 of the head and thorax of the two known species. At 

 the same time some additional characters will be made 

 known and a new form allied to Zalobius described. 



The two species differ greatly in the form of the thorax, 

 as will be seen by reference to the plate. On both the 

 disc is quadricostate, the costas abbreviated and indistinct 

 in spinicolUs, entire and well marked in serricollis. 



The terminal joint of the maxillary palpi is scarcely 

 twice as long as the third joint, although Dr. LeConte 

 gives it greater length. The gular sutures coalesce at 

 their middle, forming but one, as will be observed in all 

 the genera in our fauna of the sub-tribe Coprophilini, of 

 which Zalobius is a member, as stated by LeConte. The 

 outer five joints of the antennae are described as rather 

 abruptly wider (Class. Col. N. A., ed. 1883, p. 103), 

 while in Syntomium but three joints are so. While this 

 character is fairly good, it will be observed that the 

 structure of the joints themselves affords a more certain 

 character. In Zalobius the last four joints have the 

 dense punctuation indicating their sensitive character; 

 the joints one to seven are smooth, and in s-pinicollis 

 without hairs, in ser7'icollis somewhat hairy. In Synto- 

 mium the last three joints have the dense punctuation, 

 the other joints glabrous but hairy. 



It will also be observed that the head is considerably 

 prolonged behind the eyes in both species of Zalobius, 

 suddenly narrowed to a neck, while the head is not capa- 

 ble of retraction on account of the elevation of the back 

 of the head above the neck. Of the genera of Copro- 

 philini, Coprophilus is the only one with spinules on the 

 outer edofe of the tibise. 



