Mr. R. H. Meade on the British species 0/ Phalangiidse. 395 



genera and species : I shall not enter however at any length into 

 the anatomy of the Phalangiidse, hut must refer any of my 

 readers who are anxious to obtain more information on this 

 head, to an elaborate paper by Mr. Alfred Tulk on the " Ana- 

 tomy of Phalangium Opilio" published in 1843 in the 12th 

 volume of the ' Annals and Magazine of Natural History/ 



The Phalangiidse, which belong to the Tracheary division of 

 the Arachnidse, bear a considerable external resemblance to true 

 Spiders, but differ in having much longer and more slender 

 legs ; in the abdomen being sessile or attached to the whole 

 breadth of the cephalothorax, and destitute of spinnerets at its 

 extremity; in having only two eyes, which are elevated on a 

 common peduncle ; and in having the mandibles or falces fur- 

 nished with didactyle forceps. 



The dermo-skeleton consists as in the Spiders solely of tough 

 integument, but differs in being divided into rings or segments, 

 generally very distinct on the abdomen, and marked with trans- 

 verse rows of small projecting cells, tubercles, or ocelli. The 

 body is of an oval or rounded shape and somewhat depressed. 

 The cephalothorax and abdomen appear at first sight to be com- 

 posed of a single piece, there being little or no constriction be- 

 tween them ; but when closely examined, a strongly marked 

 groove or ridge will mostly be seen separating the first ring of 

 the abdomen from the plate or buckler covering the upper sur- 

 face of the cephalothorax. The species are mostly of a sombre 

 colour, varying from black or gray to brown and yellow. The 

 upper surface of the abdomen is mostly marked by a wide lon- 

 gitudinal dorsal band (vitta) of a darker colour than the rest of 

 the back, differing in shape in different species, but generally 

 wavy or dentated at the edges. This band often extends for- 

 wards to the cephalothorax; sometimes it is indistinctly seen, 

 but some traces of it may almost always be distinguished. The 

 cephalothorax, which constitutes about a third or fourth of the 

 length of the body (being proportionally much larger in the 

 males than the females), is trapezoid in form, being narrower in 

 front, where it is generally excavated or concave, and having the 

 sides prolonged backwards and outwards. The lateral edges are 

 surrounded by a sinuous or wavy border, on which, opposite the 

 attachment of the first pair of legs, are seated two stigmata or 

 spiracula, which were clearly described by Latreille, but have 

 since been sometimes mistaken for cornea or simple eyes. The 

 eyes, two in number, are large and simple, and seated upon an 

 eminence or elevation placed nearly in the centre of the cephalo- 

 thorax; one eye being placed laterally upon each side of the 

 eminence, which is mostly semicircular in shape, and surrounded 

 by a double crown or crest, which is armed with tubercles or 



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