2.2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 73 



Latreille, 1795 (Mag. encycl., v. 4, p. 7) and 1796a (Precis) pub- 

 lished two papers in which he cited single species as examples for var- 

 ious acarine genera, and these examples are interpreted by some 

 authors as definite designations of type species for the genera in 

 question. 



For the generic names which are new in these two papers this in- 

 terpretation is undoubtedly correct, for these particular genera are 

 monotypic by original publication. But for those generic names which 

 are old — namely, published prior to these two papers — citation of the 

 species is not made in sucli a way that they can be interpreted as 

 types under the following provision of Article 30g : " The meaning 

 of the expression ' select the type ' is to l)e rigidly construed. Mention 

 of a species as an illustration or example of a genus does not con- 

 stitute a selection of a type." Accordingly, for the older genera these 

 citations are to be interpreted as examples, not as type species. With 

 this conclusion in mind some of the existing confusion can be 

 cleared. 



Sarcoptcs Latreille, 1802b, Hist. nat. dTns., v. 3, 67, was first pub- 

 lished as monotypic, namely mt. Acarus scahici. Article 30c. 



In the same publication Latreille (1802b) cites (p. 64) Acarus 

 example A. siro syn. Tyroglyphus 1796, mt. Acarus siro and (p. C2) 

 Siro Latreille, 1795, 19, with Siro ruhcns Latreille; as ruhcns is the 

 first and only species mentioned with the generic name Siro it be- 

 comes automatically the type of Siro. See Art. 30g and Opinion 46. 



This publication of 1802 definitely fixes the type species of 

 Sarcoptcs. 



The type species of Acarus was first definitely designated by 

 Latreille, i8ioa, p. 425, when he cited as type Acarus siro from 

 which scabici was eliminated, thus leaving siro in the sense of farinae. 



The question at issue can be closed with the works of Latreille, 

 1802 and 1810, but for a clearer understanding of the various com- 

 plications which have arisen the following table of historical data is 

 given herewith. 



Acarus Linn., 1758a, 344, 615, with 31 species, including siro (with 2 varieties, 



farinae [tsd.j and scabiei [eliminated]). [OI)jective syn. Tyroglyplius 



Latr., 1802, mt. siro (i.e., farinae).] 

 1795: Acarus coleoptratus Linn., 1758a, 616, no. 13, cited as example (not as 



type) by Latreille, 1795, Mag. encycl., v. 4, 19. [Cf. Notaspis Llerm.. 



1804]. Some authors have construed this as type designation. 

 1796: Acarus cjcniculatus Linn., 1758a, 617, no. 17, cited as example (not as 



type) by Latreille, 1796a, 184. Some authors have construed this as type 



designation. 

 [1796: siro [not scahici] nit. of Tyroglyphus liy Latreille, 1796a, 185.] 



