ON SOME RAEE ARACHNIDS 427 



found as I expected that both species were represented. In 

 this Mr. Cambridge agrees with me. They can easily be 

 distinguished, firstly by general facies and coloration, and 

 secondly by the structure of the copulatory organs. Both 

 species are carefully described and figured by Chyzer and 

 Kulczynski*, and Bosenbergf . I here give a few comparative 

 figures of both, because A. Sturmii is now for the first time 

 recorded as British, and because I have discovered a difference 

 in the palpal organs which is unnoted by earlier writers, and 

 which renders the separation of the males as easy as that of 

 the females. The differences in the facies and coloration 

 are best marked in the females, and the following notes apply 

 to that sex. In the males the same differences may exist, but 

 are generally much less distinct, and they cannot be 

 separated by facies alone. In the female sex both spiders 

 are of about the same size, ranging in my examples from 

 4 mm. to 6 mm. In each there is a very slight prominence 

 or hump on each side of the abdomen, such as occurs in a 

 very much more developed condition in A. gibbosus (Walck.), 

 where it forms a distinct tuberosity. This gibbosity is in both 

 cases very slight, but it is a little more marked in A, 

 triguttatus than in A. Sturmii. The abdomen of the former 

 spider is therefore rather more angular than that of the latter, 

 which is often nearly globular. The abdominal pattern is 

 similar, but not quite the same in the two species. The 

 prevailing colour in triguttatus is yellowish, with brown, 

 usually dark brown, markings. A very broken and some- 

 times almost obsolete yellowish white line on each side of the 

 anterior part of the abdomen cuts off obliquely a dull brown 

 patch. These patches thus occupy respectively each side of 

 the anterior part of the abdomen. Three or four similar, but 

 not so deeply tinted patches occupy the dorsal surface on 

 each side of the middle line. These grow smaller and nearer 

 together as the spinners are approached. A central much 

 branched yellowish brown stripe may also be present, but this 

 is often obsolete. 



* Araneae Hungarise, Tome 1, pp. 119, 12G, 127, Tab. V., figs. 5, 6. 

 t Die Spinnen Deutschlands, pp. 38, 39, Taf. II., figs. 25, 26. 



