34 CALIFORNIA ACADEMY OF SCIENCES. 



plete, and the colored illustrations leave much to be de- 

 sired in the way of accurate detail. Piaget's monographic 

 essay is easily the most valuable treatise on the group, 

 the descriptions being good, the uncolored figures in 

 every way admirable, and the scope of the work truly 

 monographic. Piaget has fairly attempted to include in 

 his original essav a consideration of every species of 

 Mallophaga described up to 1880. In his Supplement he 

 publishes the descriptions of more than 100 new species 

 which have come under his observation. Taschenberg's 

 memoir is the first part of what he hopes to make a com- 

 plete monograph of the group. It includes the genera 

 Gomodes, Goniocotes, I^/'peitrus, Ornithobius, Akidoproc- 

 tus and Trichodectes. . The descriptions of new species 

 are very complete, and the keys to species in the consid- 

 ered genera of great value ; the illustrations only, though 

 good, are not up to the exceptionally high standard of 

 the work. Taschenberg, like Giebel, has had access to 

 Nitzsch's types. 



Of the lesser systematic memoirs Nitzsch's posthumous 

 papers, edited by Giebel, in the Zeitschrift fur gesammte 

 Naturwissenschaft, vols, xvii, 1861, xviii, 1861, and xxviii, 

 1866, are the most important; all of their contents are, 

 however, included in the Insecta Epizoa. Next in im- 

 portance, as far as number of described species goes, are 

 Rudow's papers, consisting of an inaugural dissertation 

 (1869) and several articles in the Zeitschrift fur gesammte 

 Naturwissenschaft, 1869- 1870. Rudow's descriptions 

 are deplorably incomplete ; Piaget has practically dis- 

 carded them in his monograph. Of treatises on the Mal- 

 lophaga to be found in text-books of general entomology, 

 that in Burmeister's Handbuch der Entomologie, 1832, is 

 markedly the most complete. 



Finally, of morphological memoirs, those of Kramer on 



