DESIS MARTENSn. L. Koch. 
tSyz, Desis maHenm^ L. Koch, Die Arachn. Austral., I., p. 347, pi, xxix,, figg. 2-29. 
1894- j» Thon Arachnider fran Java, etc, p. 5. 
Description of Plate 74 $ — a, spider, mag, ; natural size ; r, profile \ cephalo- 
thorax underside ; eyes \ epigyne ; jf, ^ right palpus ; nest in coral in disused 
lithodomus burrow. 
? Total length, 12 ; cephalothorax, 6 ; breadth, 4 ; do. in front, 2 \ abdomen, 6 ; 
breadth, millim. Leg, i, — 18; ii. — ; iii. — 15^^ ; iv. — 18 millini. Patella +tib!a, 
iv. — 6 mitlini. 
$ Total length, 8 ; ccphalotborax, 5 ; breadth, 2 \ do. in front, \ abdomen, 4)^ ; 
breadth, milltm. Leg, i.— is;n- — 10 ; iil,^ — 9^^ ; iv. — 13 millim. Patella + tibia, 
iv, — 4 millim. 
This spider was found by me on the Blacka Mati coral reef off the New Harbour, 
Singapore, the place where it was first discovered by Dr. Martens in 1861. Dr. L, Koch 
points out in his Arachniden Australiens, in a very interesting way, page 350, that this 
spider, though living on a coral reef, is not by any means a water spider, and accurately 
surmises the way in which it lives. I found that it was perfectly helpless when placed in a 
bottle of water, showing in every way that it was not in its natural element. It lives in 
holes made by a species of lithodomuSf and spins a matted web across the hole, and so 
keeping an air chamber for itself during flood tide. It is found in considerable numbers, 
but as it runs with great rapidity, is very hard to catch. 
