1890.] ACARINA FROM ALGERIA. 421 



form of the shells of some of the limpets (wheace the name I have 

 given to the species). There are two longitudinal curved rows of 

 short, thick, almost straight hairs on the notogaster, so arranged as 

 to appear to form a ring round the abdomen when seen from the 

 side (see Plate XXXVIII. fig. 3). Genital and anal plates of nearly 

 equal size, almost square, close together, and occupying nearly the 

 whole length of the ventral plate. 



Almost all the thick hairs on the creatures are slightly rough or 

 serrated if seen by a high amplification. 



When the creature is alive the true form of the abdomen is 

 scarcely seen, as mud is plastered on the hinder portion of that 

 region, concealing the shape, and this mud is not irregularly placed, 

 but is generally so affixed as to make the abdomen appear a thick 

 flat oblong. 



I have three or four specimens from the neighbourhood of Algiers, 

 and from Blidah, Algeria. 



Dam^us phalangioides, n. sp. (Plate XXXVIII. fig. 1.) 



Length about "52 millim. 



Breadth about '22 millim. 



Length of legs, 1st pair about 1'30 millim. 

 „ 2ud „ -80 „ 



„ „ 3rd „ 1-05 „ 



„ _ „ 4th „ 1-50 „ 



This species is remarkable for its extremely long and slender legs. 



Colour yellow-brown, of medium depth. 



Texture smooth, but not polished. 



Cephalothorax distinctly divided into two parts — the rostrum, 

 which is somewhat conical, and the larger hind portion, which is 

 more globular. Rostrum rather blunt-pointed, with two pairs of 

 long fine rostral hairs ; the second pair almost at the posterior limit 

 of the rostrum. Pseudostigmata small cups, considerably raised, 

 and almost transparent. Pseud ostigmatic organs setiform, flexible, 

 extremely long and fine, about the same length as the bod}' without 

 the rostrum. Interlamellar hairs placed close to the inner sides of 

 the pseudostigmata, and similar to the pseudostigmatic organs, 

 but even finer and not quite so long. 



Legs extraordinarily lovg a.ndjine. Femora with very long thin 

 peduncles of almost equal thickness throughout, and elongated clubs. 

 Genuals and tibife scarcely clavate. Tarsi of the first and second 

 legs considerably, those of the third and fourth slightly, enlarged 

 near the proximal ends ; toward the distal ends they are all 

 remarkably thin, and are singularly curved or undulated, par- 

 ticularly the fourth pair. Claws monodactyle, very fine. There 

 are a few setiform hairs on the various joints, mostly black, those 

 on the fourth legs being the largest. 



Abdomen a short ellipse without markings, but with two longi- 

 tudinal rows of hairs, of which those constituting the anterior and 

 central parts of each row are black, short, and curved ; those form- 

 ing the posterior portion longer, more flexible, and lighter in colour. 



Proc. Zool. Soc— 1890, No. XXIX. 29 



