ON NEW OR LITTLE-KNOWN ACARI. 359 



Rhinonyssus waterstoni, sp. n. (Text-fig. 2.) 



$ . Abdomen not elongated. Very minute spinules are present 

 on the venter in this species, instead of the hairs that are present 

 in R. caledonicus. Gapitulum short ; segments of palp very- 

 short, being very much wider than long; tarsal segment very 

 small, the conical tubercle on it well developed. Legs not very 

 long, the first pair apparently slightly shorter than the fourth. 

 Coxa? with very short spinules or hairlets instead of the fairly 

 long hairs present in R. caledonicus. Spines on legs much weaker 

 than in R. neglectus. Claw of first leg apparently without any 

 dorsal process. 



Length '96 mm. 



Habitat. Nasal cavities of the Razorbill (Alca torda), Ollaberry, 

 North Mavine, Shetland Islands. Specimens collected by James 

 Waterston (15. xii. 1913). 



Rhinonyssus echinipes, sp. n. (var. of R. neglectus?). (Text- 

 figs. 3 & 4.) 



5 . Abdomen not very elongated in the female sex. There are 

 three pairs of minute denticles or tubercles anteriorly on the 

 venter. The three pairs of denticles in front of the anus are 

 much smaller and weaker than in R. neglectus. Capitidum 

 apparently shorter than in R. neglectus. Segments of the palp 

 also shorter ; the minute conical tubercle on the tarsus is un- 

 usually large in this species. Legs. Denticles on posterior coxa? 

 weaker than in R. neglectus or replaced by hairs with a somewhat 

 thickened base ; the other segments of the legs furnished with 

 numerous strong denticles as in R. neglectus. 



S . Abdomen apparently more elongated (conical) than in the 

 female. 



Length, 6 1'36 mm., $ 1"36 mm. 



Habitat. Nasal cavities of Ringed Plover (^Egialitis hiaticola), 

 Queyfirth, North Mavine, Shetland Islands (5. i. 1914). Speci- 

 mens collected by James Waterston. 



Rhinonyssus neglectus, sp. n. (Text-fig. 5.) 



5 . Abdomen not elongated. Three pairs of strong but short 

 spinules are present anteriorly on the venter, and three pairs of 

 very strong spinules (grouped closely together) are placed imme- 

 diately in front of the anal aperture. Capitidum unusually 

 elongated. Palpi with the segments more slender than in R. 

 echinipes. Legs. First and fourth pairs of legs rather long, being 

 considerably longer than the second and third pairs. Denticles 

 on legs much stronger than in R. caledonicus and R. toaterstoni. 



Length 1'36 mm. 



Habitat. Nasal cavities of Tringa striata (Purple Sandpiper), 



