164 CALIFORNIA ACADEMY OF SCIENCES. 



crotalns (Zool. Garden of Rotterdam) and consanguineum 

 (Les Pediculines, Supplement, 1885, p. 116, pi. xii, fig. 

 7) found on P. erythrorhynchus (dried skin in Museum 

 of Leyden). Picaglia has described a third species rag- 

 azzi (Atti d. Soc. d. Nat. d. Modena, 1885, serie iii, vol. 

 ii) found on P. trachyrhyrichus (Callao), and has estab- 

 lished the subgenus Piagetia for the group. The char- 

 acters of the subgenus are as follows: " abdomen narrow 

 and very elongate; male longer than female; length more 

 than 5 mm." The remaining members of the genus 

 Menopon present in contrast these characters: " abdomen 

 oval-elongate, rounded oval, or almost round ; male smaller 

 than the female; length varying from 1 to 3 mm." The 

 species chiefly used by Franz Grosse in his study of the 

 anatomy of the Mallophaga was a member of this Meno- 

 pon titan group, taken from a Pelican, undetermined, 

 from Chile. 



It certainly seems advisable to indicate the peculiar 

 characters of the group by assigning to it a subgeneric 

 name; but I can hardly recognize in Picaglia's descrip- 

 tion of ragazzi characters other than the dimensions 

 which make it recognizably distinct from titan. My 

 specimens from Pel. erythrorhynchus show the slight vari- 

 ations from titan indicated by Picaglia in his description 

 of ragazzi, but the dimensions are quite as large as those 

 of titan (Picaglia made ragazzi one -fourth shorter than 

 ti/a)i) ! My specimens from Pel. californicus closely cor- 

 respond with Piaget's description of titan, except that the 

 transverse abdominal blotches are not bifurcated at the 

 extremities. I believe that the present knowledge of the 

 group hardly justifies any separation of the known forms 

 into distinct species, but that the presence of these varia- 

 tions may be recognized by letting titan stand as the rep- 

 resentative form of the species (consanguineum is evidently 

 a distinct species, the equality in size of both sexes re- 



