British Oribatidas. By A. D. Michael. 33 



year 1879 I have continued to investigate the same subject, and, 

 as I expected, I find that the field is far from being exhausted ; 

 indeed, material pours in upon me much faster than I can deal 

 with it. 



I must first of all thank Mr. Greorge, of Kirton Lindsey, for 

 the assistance he has rendered me by sending specimeas, both 

 mature and in earlier stages. 



I have devoted myself greatly to tracing the life-histories of the 

 various species, as any knowledge based upon an acquaintance with 

 the adult only, is necessarily imperfect, although I am not able to 

 follow Megnin * to the extent of his expressed opinion that no one 

 should name a species of Aearina unless he is acquainted with the 

 larva, nymph in all stages, and adult male and female, and that all 

 names not based upon such a knowledge may be disregarded ; it 

 seems to me that such a rule would be attended with grave incon- 

 veniences, but I fully agree with him that the knowledge of the 

 life-histories is of the greatest importance, and, among the 

 Orihatidai, the nymphs are often so singular and interesting that 

 they would be well worth the attention of the naturalist for them- 

 selves alone. 



My own searches and observations during 1879 have been 

 conducted at Epping Forest, the neighbourhood of Tamworth, and 

 at the Land's End, Cornwall. Mr. George, as before, has collected 

 at Kirton Lindsey, in Lincolnshire. 



I am not aware that since my last paper any further biblio- 

 graphy has appeared which it is necessary to notice. 



Life-histories. 



As far as I am aware, the only writers who have made any 

 attempt to study this subject with respect to the Oribatidin have 

 been Nicolet t and Claparede.$ The former traced the nymphs of 

 eleven species, and, as far as my experience yet goes, very correctly, 

 with the exception of Nothrus sylvestris and N. imlustris, as to 

 which I have a few words to say in a later part of this paper. He 

 makes some other assertions as to nymphs which he has not 

 actually traced, which I hardly think are quite so happy. 



Nicolet's coloured illustrations of the nymphs are extremely 

 good ; of course it would naturally happen, with the first person in 

 the iield, that those nymphs which he would trace would be chiefly 

 the most common and most easy to breed, and this is so with the 

 majority of Nicolet's species. 



* " Mt'iiKiirc sur Ics Ilyjioiics," Robin's ' Journal do rAnatnniio ot do ]a 

 Physiologic,' 1871, p. 225 ct scq. " Mc'moiru sur lus Gauiasidi'.-^," ibid., ISTlJ, 

 p. 2811, &c. 



t ' Arohivos du Musoura,' 18.55, t. 7. 



X "Studicu uu Aoaridcn," iu ' Zcitschrift fiir wiss. Zool.,' 18G8. 

 VOL. III. D 



