416 NOTES AND MEMORANDA. 



indicating the slight value which can be attached to such broad 

 generalizations as that just stated, 



Ludwig Graif, in his work on Myzostoma (Leipzig, 1877) proposes 

 to unite that form with the Linguatulida and Tardigrada into a 

 group, intermediate between Arthropods and Vermes, for which 

 he suggests the name StelecJiopoda. So much on the one hand : on 

 the other, a larval Pentastomum (the most important, if not the only 

 genus among Linguatulids) has been found in the human liver, and 

 others in that of the hare and like forms, while the nostrils of dogs 

 and the lungs of the boa are also well-known homes for these 

 curious forms. In the paper now to be examined, descriptions are 

 given of several species of Acari, which have been found in the more 

 internal organs and tissues of birds ; the first to describe any of these 

 forms was the Italian zoologist Gene, who, in 1845, gave an account of 

 a form which infested every specimen of Strix fiammca found in the 

 neighbourhood of Turin ; the number found in the tissue underlying 

 the skin aj^pears to have been enormous, but no lesions could be dis- 

 covered by which they might have entered ; the skin, curiously enough, 

 retained its natural colour, and the superjacent feathers exhibited no 

 alteration of form or colour. To this form Gene gave the name Sar- 

 coptes strigis, and he compared it with the form, S. nidulans, described 

 by Nitzsch ; this comparison was not very full, but this again is hardly 

 a matter for astonishment, as it has since been shown that Nitzsch's 

 form was not a Sarcoptes at all. The parasite on the Turin Strix is 

 described as being only -/„ of a line in length, of a pearly white, with 

 the body convex superiorly, and flattened inferiorly. 



In 1866 another form was described by Mr. Eobertson, of the 

 University Museum, Oxford, who discovered it in the pigeons which 

 were provided for the instruction of the students of that Institution ; 

 this was said to be visible to the naked eye, white and vermiform ; its 

 chief abode was the subcutaneous connective tissue around the great 

 veins of the neck, and the region of the pericardium. A critical study 

 has shown that Robertson's form was described by Filippo de Filippi 

 in the year 1861, under the name of Hypodectes nycticoracis ; in 1872 

 M. Slosarski, of the University of Warsaw, examined the parasite of 

 the pigeon, and, while giving a new name, confirmed the statements 

 of the Oxford anatomist as to the absence of distinct internal organs, 

 and of the large quantity of granular vesicular sarcode which filled its 

 interior. 



The observations of M. Megnin himself were commenced at the 

 instigation of M. Alph. Milne-Edwards, in the same year (1872), and 

 the bird examined was Lophjrus coronatus. Here the forms described 

 by Robertson and Slosarski and by Professor Gene appear to have 

 been found together. As it is impossible to give a detailed account 

 of his observations, we will deal with the more interesting of the 

 two; this was not half the size of the other, the mouth was much 

 more rudimentary, the integument smooth and diaphanous, and no 

 trace of an anus was evident ; this curious form can only be 

 explained by reference to the life-history of the Acarina, in which 

 there are a succession of stages, which are nothing less than 



