ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 585 



Chorioptes (or Symbiotes) on Birds.* — M. L. Trouessart, remarking 

 that Sarcoptes is the only acarid that has yet been certainly found on birds 

 now directs attention to the discovery by MM. Rivolta and Caparini on 

 fowls, of two acari which they call Epidermoptes bifurcatus and E. hilobatvs ; 

 the latter is synonymous with Symhiotes avium ; these creatures appear to 

 the naturalists just named to be the cause of grave attacks of psoriasis. 



M. Trouessart, however, agrees with M. Neumann, that the psoriasis is 

 rather due to Achormi Schonleinii, and thinks that the figures given of 

 Epidermoptes show that that genus has not the form either of rostrum or of 

 limbs which is proper to the fossorial habits of the psoric species, and that 

 its facies is that of a plumicolous sarcoptid. 



On Passer domesticus there lives, as there probably does on a number of 

 other birds, a species which certainly belongs to the genus Chorioptes 

 (Gervais) or Symbiotes (Gerlach) ; it is found at the point of insertion of 

 the primary feathers, and does not seem to penetrate deeply into the skin ; 

 it is proposed to call it C. avus. On P. domesticus there is a very small 

 Pterotichus which may be called P. dermicola, as it lives under the skin of 

 the body. 



Sarcoptes laevis-t — Prof. A. Eaillet gives an account of a new acarid 

 found parasitic on the pigeon and the fowl. This new species is very 

 closely allied to Sarcoptes mutans, but appears to differ in having only one 

 larva at a time ; it is also smaller than ;S^. mutans, though larger than 

 S.fossor; it approaches the latter, and differs from the former species by 

 the absence of cutaneous papillfe on the notogastrum of the female. The 

 most important character, however, is the presence of two copulatory suckers 

 on the male, for this is a very exceptional, though not unique, possession in 

 the genus Sarcoptes. The mode of life of this new species shows that the 

 name of plumicolous Sarcoptidfe is not exclusively applicable to the 

 Analgeringe, for S. Isevis lives in the follicles of feathers. The author is of 

 opinion that the presence or absence of copulatory suckers in a given form 

 is not sufficient to justify the creation of a new genus, or even of a special 

 section of an old genus. 



Stage in the Development of Galeodes.t — Herr A . Croneberg describes 

 a somewhat remarkable stage in the development of Galeodes araneoides ; 

 the si)herical abdomen forms the chief mass of the contents of the egg and 

 the broad and flattened cephalothorax with the folded palpi, and the legs 

 are pressed down on the lower surface of the abdomen. The aj)pearance of 

 young which have just escaped gives the impression of a contraction of the 

 abdomen having driven part of the fluids contained in it into the anterior 

 part of the body, the appendages of which have thereby become suddenly 

 extended ; the abdomen is now seen to be of an elongate egg-shape, and 

 to have some slight constrictions. The cuticle is shown to be pro- 

 visional by the complete absence of all the setae and hairs which are so 

 numerous in the adult ; along the back alone is there a double row of 

 twelve setfe. The appendages have as yet no distinct sign of seg- 

 mentation, and there are no indications of the abdominal limbs. The 

 rostrum is stout and broad, and is completely devoid of the complicated 

 setal apparatus at its tip ; the highly chitinized pharynx is provided with 

 projecting chitinous ridges, and so calls to mind the structure of the 

 Pseudoscorpions. Most remarkable is the presence of a pair of flat, wing- 

 like appendages, about • 5 mm. long, which are inserted on either side of 



* Comptes Eendus, civ. (1887) pp. 921-3. 



t Bull. Soc. Zool. France, xii. (1887) pp. 127-3G (1 pi.). 



; Zool. Anzeig., x. (1887) pp. 163-4. 



1887. 2 Q 



