OCR Text |
Show 1890.] ACARINA FROM ALGERIA. 421 form of the shells of some of the limpets (whence 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^TJS PHALANGIOIDES, n. sp. (Plate XXXVIII. fig. 1.) Length about '52 millim. Breadth about '22 millim. Length of legs, 1st pair about 1*30 millim. „ 2nd „ -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. Pseudostigmatic organs setiform, flexible, extremely long and fine, about the same length as the body 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 long and fine. Femora with very long thin peduncles of almost equal thickness throughout, and elongated clubs. Genuals and tibiae 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, particularly 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 longitudinal rows of hairs, of which those constituting the anterior and central parts of each row are black, short, and curved ; those forming the posterior portion longer, more flexible, and lighter in colour. PROC. ZOOL. Soc-1890, No. XXIX. 29 |