192 BEITISH TYROGLYPHIDTR. 



GENUS LENTUNGTJLA * (Michael). 



Lentungula, 1893. " On a New Genus and Species of Acari found 

 in Cornwall," in ' P. Zool. Soc.,' London, 

 1893, pp. 262267, pi. xviii. 

 1897. Berlese, ' A. M. S. Crypt.,' p. 103. 



1894. Lohmann, in ' Wissenschaftliche Meeresunter- 



suchungen von d. Biol. Anstalt auf Helgo- 



land,' vol. i, Heft 1, pp. 8691, pi. iv. 

 1899. Kramer, ' Thierreich,' Lief. 7, p. 136. 



In 1889 Megnin originated a genus, Hyadesia,^ for 

 a creature closely allied to that upon which I based 

 Lentungula. Megnin's genus was avowedly founded 

 upon an immature form. Megnin had not any adults. 

 Unfortunately it was published, not in the part of the 

 c Mission Sci. du Cap Horn ' relative to Acari, but 

 separately, at the end of the Protozoa, without any- 

 thing external on that part to indicate that the con- 

 tents were other than Protozoa. Thus I missed it, and 

 was not aware of its existence when I wrote my paper 

 in 1893 ; had I known of it I certainly should have 

 referred to it ; and although, for the reasons given on 

 page 187, I could not have recognised a generic or 

 specific name in the Acari founded upon an immature 

 type, I should have endeavoured to preserve Megnin's 

 name, either by adopting it for the adult (if that be 

 permissible), or in any other possible manner, if I had 

 been sure of the identity of the two genera. As to 

 this, however, there seems to be very grave doubt, in 

 spite of the great general resemblance ; because Megnin 

 states as one of the principal characteristics of his genus 

 that there is not any line of demarcation between 

 cephalothorax and abdomen, whereas in Lentungula 

 that demarcation is extremely strong. This has usually 

 been recognised as a difference of at least generic 

 importance in the Acarina, although there are creatures 



* Lentus, flexible ; ungula, a little claw. 



f " Note sur un Acarien de la Terre de feu Hyadesia uncifer" ' Miss. 

 Sci. Cap Horn,' vol. vi, part 3, Protozoaires, at end of part. 



