554 APPENDIX C. 



work M. Piaget has described three species of Mallophaga from 

 S. serrator, and four from S. leucogastra (Brown Booby) (Vol. I., 

 pp. 108, 337, 339, and 490). He also enumerates, and figures, 

 four species from S. bassana, to which he assigns the following 

 names : — 



Docophorus lari, Denny [Plate IX., Fig. 7]. 



Docophorus bassance, Denny [Plate X., Fig. 6]. 



Lipeurus pullatus, Nitzsch {= L. staphylinoides, D.) [Plate 



XXVII., Fig. 9]. 

 Menopon pustulosum, N. [Plate XLL, Fig. 3]. 



Mr. William Evans, of Edinburgh, whose researches are still 

 more recent, and who has afforded me the greatest assistance 

 in a subject of which I am very ignorant, is of opinion that 

 Denny's Docophorus bassanie is the female of his Lipeurus staphy- 

 linoides {L. pullatus, N.). See his paper in " Proc. R. Phys. 

 Soc. of Edinburgh " (1912, p. 273). 



All the Mallophaga which Mr. Evans has so far obtained 

 from Gannets have been referable to these two forms, for 

 the Lipeurus which he recorded from St. Kilda in the 

 " Annals of Scottish Nat. Hist." (1906, p. 87), proved not to 

 be a Gannet species, but to be L. ynutabilis from the Fuhnar 

 Petrel. 



GanneVs subcutaneous Acarid. — ^Quite distinct from these 

 insects, or Mallophaga, is the Singular Mite or Acarid, which 

 is to be sometimes found in the subcutaneous cells of the 

 Gannet. This little creature, Avhich was first brought under 

 the notice of naturalists by George Montagu, who described 

 it in "The Memoirs of The Wernerian Nat. Hist. Soc," 

 (1809, I., p. 191), is worthy of more study than it has yet 

 received. It may easily be overlooked, owing to its small 

 size and pale colour, and it certainly is not of universal 

 occurrence. 



