382 OLIGOCIIAKTA 



genus srnsn stricto is its exceeding activity. The first speci- 

 mens ever noticed in this country, or at least of whose exist- 

 ence printed notice was taken, were exhibited by the late Dr. 

 Baird of the British Museum, at a meeting of the Zoological 

 Society. He remarked in that communication upon the agile 

 fashion in which these tropical Amu-lids will spring off a table 

 when touched or in any way interfered with. Numerous other 

 observers have seen the same manifestations, and the name of 

 " eel-worm " has leen given to these Pcrichaeta by gardeners. 

 It is worth putting on record here that in a species of Acan- 

 thodrilus (A. capcnsis) the same irritable behaviour is visible. 

 "When a Pcrichacta moves it helps itself greatly by extending, or 

 rather protruding, the buccal cavity, which serves as a sucker, and 

 grips the ground in front until the rest of the body is brought for- 

 ward. It is possibly on account of this extra facility for movement 

 that the genus can climb trees with such ease. A species of 

 Pcrichacta has been recorded by Mr. Willey upon an epiphyte of 

 a palir, and Dr. Benham has found that it is a new species, to 

 which the name of Pcrichacta willeyi has been given. The 

 Lumbricid genus (if it be admitted as a genus), Dcndrobaena, was 

 so named on account of a similar habit of climbing trees. Very 

 singular in its habit is the not inaptly-named Perichaeta musica 

 of Java. It is a monster of its kind, several feet in length, and 

 during the night makes " a sharp interrupted sound," apparently 

 by the friction of the chaetae against stones. The species 

 figured (p. 381) is, as are a few others, remarkable for the presence 

 of twelve or seventeen sperrnathecae in segments 6 and 7. 



FA.M. 10. Cryptodrilidac}- This family is one of the largest 

 of the Oligochaeta; there are rather over 120 different species, 

 which can be arranged in at least sixteen genera. They are 

 found in most parts of the world, but abound principally in the 

 tropics. Australia may be considered to be the headquarters of 

 the family, which form its principal earth worm -inhabitants. 

 Peculiar to this continent, or at least mainly confined to it, are the 

 genera M^eytiscolidcs, Cryptodrilus, Fl etcher odrilus, Trinephrus, and 

 Disaster. Microscolex, though occurring in many parts of the 

 world, is characteristic of the more southern regions of South 

 America and of New Zealand. Tropical Africa has the genera 

 ns and Millsonia limited to itself, and has besides nearly 



1 See Fletcher and Spencer, already quoted, for Australian species. 



