Mr. W. J. Fuller on the Anatomy of Spiders. 167 



cephalo-thorax in a manner excellently adapted to the habits of 

 the various genera. The falces (mandibles) consists of two strong 

 joints attached to the fore part of the cephalo-thorax, each armed 

 with a formidable fang folding into a groove on the inner side, 

 the whole somewhat resembling a pruning-knife. A poison- 

 gland is present in the cephalic region, and connects with an 

 orifice in the fang by a straight tube. Two maxillae on the under 

 surface assist mastication, and the palpi, proceeding from the 

 outer edge, are long, five-jointed, antenna-like organs, and are 

 used as antennae normally ; but in the male, on arriving at 

 maturity, the two end joints are developed into complex organs, 

 which defy description, but will well repay investigation. These 

 are in all probability used by the male in the process of con- 

 jugation. They differ in every species, and in some instances 

 are extremely beautiful objects. The labrum is a very simple 

 organ, which completes the oral apparatus. 



The legs are arranged round a large oval sternite, which forms 

 the under side of the cephalo-thorax, and none of their coxbb 

 are in contact. They are seven -jointed and variously furnished 

 with hairs and spines all over their surface ; but on the treading 

 surface a collection of hairs is frequently found, which are of 

 service for travelling over smooth surfaces. There are also, at 

 the tip of the tarsus, two or more pectinated claws, which in 

 some cases are curiously shaped. The hairs of the leg are 

 varied in shape, being sometimes club-shaped, frond-like, 

 toothed, &c. In the Ciniflonidce the last joint but one is fur- 

 nished with a double row of spines, arranged so that the points 

 of one row may approximate to the points of the other. This 

 apparatus, called the " calamistrum," is used by the spider for 

 carding the web as it is spun, and so producing a beautiful 

 flossy web. The spinning apparatus consists of six or eight 

 mammillae, fixed at the extremity of the abdomen, on the sunimit 

 or interior surface of which are numerous spinnerets or jets, 

 supphed with a quickly- drying fluid by numerous glands, situated 

 in the lower posterior part of the abdomen. When the spider 

 wishes to make a web, it applies the mammillae spread out like the 

 fingers of a hand to the surface of some convenient body ; fila- 

 ments from hundreds of spinnerets are attached to the body, and 

 elongated as the spider proceeds ; in some cases these filaments 

 are combined into one thread, or they may be woven mto a 

 complex mass of floss web by the calamistrum. The Epeirida 

 and others bead their web by causing large masses of web to 

 agglomerate at certaua points. At the anterior extremity of the 

 abdomen, on the under surface, are found one or two pairs of 

 transverse slits on either side the median line, and on either 

 side of the opening of the generative organs. These shts are 

 the stigma or openings of the Branchia, which consist of book- 



