Cambridge. — On the Spiders of Neio Zealand. 189 



curious row of short closely-set curved spiny bristles along a portion of the 

 upper side of the metatarsi of the fourth pair of legs. The use of this row of 

 bristles (called the calamistrum) is alluded to further on. 



The length of the legs in spiders is very various, both actually and 

 relatively, and the differences between them, as well as their armature and 

 terminal claws, fui^nish valuable characters, often generic and always 

 specifically important (f. 10, 17). 



The Palpi are two (in many species leg-like) limbs of five, or (counting the 

 basal piece, to which each is articulated) six joints (f. 7, 8, 9). The basal 

 piece, situated immediately behind the falces, forms a maxilla (f 83/, and %y) 

 on either side of another piece, the labium (f. 2h, and \bh). This latter is 

 various in form, and always present, except in a new and remarkable spider 

 lately received from Brazil — Aphantochilus, Cambr. — in which the labium is 

 wanting, the maxillae in this instance closing up to each other. Within the 

 labium is another portion of structure — the tongue — to which sufficient 

 attention has not yet been paid by araneologists ; by the aid of this portion no 

 doubt the act of swallowing the juices of insects, when expressed by the falces 

 and maxillae, is effected. These parts, falces, Ttiaxillce, labium, and tongue, 

 thus form the mouth of a spider. The maxillce are various in form and size, 

 and, with the labium and general disposition of the eyes, furnish the most 

 tangible, if not the only reliable, characters for distinguishing the genera. 

 The 3rd (cubital, f. 7v, 8v, 9v) and 4th (radial, £ 7t, 8t, 9t) joints of the palpi 

 in the male are (the former often, the latter generally) characterized by pro- 

 minences, spiny apophyses or protuberances, which furnish some of the 

 strongest and most tangible specific characters in that sex (f 7tt) ; in the 

 female the palpi are simple and quite pediform, generally terminating with 

 a single claw. The last (or digital) joint of each palpus (in the male spider) 

 is generally more or less concave (f. 8s), including in its concavity a (sometimes 

 complex) congeries of lobes, spines, and spiny processes (f 80 and I80) capable 

 in some instances of being opened out as by hinges. These are not developed 

 until the spider has come to maturity. Up to this period the digital joint has 

 a tumid and somewhat semi-diaphanous appearance, and, although generally 

 smaller, bears the same general form that it has after maturity. 



That these processes, or, as they are termed, pa^ml organs, are intimately 

 connected with the process of reproduction — the fecundation of the female 

 spider — is certain ; but the mode of their efficiency can hardly be said to have 

 been even yet satisfactorily determined. In the female the paljjus terminates 

 generally with a single claw, often pectinated ; instances, however, are frequent 

 of the absence of any terminal palpal claw. Between the plates of the 

 spiracles, and close to the fore-extremity of the abdomen on the under side, is 

 placed the external aperature of the female generative organs ; this aperture 



El 



