1874.] REV. O. P. CAMBRIDGE ON NEW DRASSIDES. 3/1 



Ceylon), eight are European, one South-American, and one North- 

 American. The larger number were intended to have been included 

 in Dr. L. Koch's work on the Drassides (' Die Arachniden-Familie 

 der Drassiden,' Niirnberg, 1866); but that work having long since 

 been discontinued before its completion, I have thought it best not 

 to delay their publication any longer. My thanks are especially due 

 to Dr. Koch for the kind readiness with which he has placed at my 

 disposal all the dissectional drawings made from the type specimens 

 for his own work ; these, supplemented with a few others drawn by 

 myself, form the materials of the Plates intended to illustrate this 

 paper. It will be observed that almost all the drawings are taken 

 from portions of the genital organs — the palpi in the males, the 

 genital aperture in the females. The form and structure of these 

 parts afford the best, and in some instances the sole reliable, criteria 

 for the determination of the species. The constant value of the palpi 

 and palpal organs of male spiders for this purpose was first pointed 

 out by our veteran araneologist Mr. John Blackwall ; and it has 

 since been abundantly recognized by all araneologists of any note, 

 though, as far as I am aware, the credit of its discovery has not 

 been sufficiently awarded by continental writers to its discoverer. 

 The form of the genital aperture in female spiders as a specific 

 character was first, I believe, made use of by Dr. L. Koch in the 

 work on the Drassides above mentioned ; and it seems likely to 

 prove a most valuable differential character with respect to "the 

 females of other groups as well as that of the Drassides. In re- 

 gard to them especially, it is not too much to say that, but for 

 this character, many species would be quite indeterminable, from 

 their great similarity in general form and colour to others nearly 

 allied. And the same remark applies to the males also, many of 

 which are with great difficulty recognizable as distinct species, 

 except by the form and structure of the palpi and palpal organs. 

 The Drassides are a very plainly coloured sombre-looking group ; 

 but few present any marked pattern or colouring ; and in the ab- 

 sence of these a well-defined and easily observed structural character 

 is peculiarly valuable. It is perhaps hardly necessary to say here 

 that these sexual and, as observed before, so strongly specific cha- 

 racters are not developed either in the male or female spiders until 

 the last moult or change of skin, when they become adult. 



Family Drassides. 

 Genus Gnaphosa, Latr. 

 Gnaphosa harpax, sp. n. (Plate LI. fig. I.) 

 Adult male, length 2| lines. 



This Spider is of ordinary form. The cephalothorax is broad 

 oval, most pointed before, and somewhat depressed ; the profile 

 slopes gradually in a curved line from the thoracic junction to the 

 eyes, and the lateral constriction forwards is but slight ; its colour is 

 yellow-brown with blackish margins ; the normal grooves and in- 



