As far back as 1859 P. Bleeker credited Java with eleven hundred species of fish; and naturalists are perpetually adding to the number.[9] In splendour and grotesqueness of colouring many kinds, as is well known, look rather like birds than fish. In the neighbourhood of Batavia about three hundred and eighty species are used as food by the natives and the Chinese, who have added to the number by the introduction of the goldfish, which reaches a great size. The sea fish most prized by Europeans is _Lates calcarifer_ (a perch). Of more than one hundred species of snakes about twenty-four species (including the cobra di capella) are poisonous and these are responsible for the deaths of between one hundred and two hundred persons per annum. Adders and lizards are abundant. Geckos are familiar visitants in the houses of the natives. There are two species of crocodiles. As in other tropical-rain forest lands the variety and abundance of insects are amazing. At sundown the air becomes resonant for hours with their myriad voices. The _Coleoptera_ and the _Lepidoptera_ form the glory of all great collections for their size and magnificence. Of butterflies proper five hundred species are known. Of the beetles one of the largest and handsomest is _Chalcosoma atlas_. Among the spiders (a numerously represented order) the most notable is a bird-killing species, _Selene scomia javanensis_. In many parts the island is plagued with ants, termites and mosquitoes. Crops of all kinds are subject to disastrous attacks of creeping and winged foes--many still unidentified (see especially Snellen van Hollenhoven, _Essai d'une faune entomologique de l'Archipel Indo-néerlandais_). Of still lower forms of life the profusion is no less perplexing. Among the worms the _Perichaeta musica_ reaches a length of about twenty inches and produces musical sounds. The shell of the _Tridacna gigas_ is the largest anywhere known.