Herriott. — Occurrence and Habits of Lepidurus viridis. 285 



Gr. M. Thomson (1879, p. 260) described two new species based on speci- 

 mens obtained from three different localities in New Zealand. The firsts 

 L. hirhii, from Wellington, was pale olive-green in colour, with carapace 

 broadly oval, very membranous, caudal setae more than half the length 

 of the body, total length 1-25 in. The second, L. compressus, from Wai- 

 kouaiti and Queenstown, Otago, was dark olive-green, with carapace oval 

 and more*or less arched, caudal setae not half the length of body, and a 

 total length of only 0-8 in. Thomson expressed some hesitation in forming 

 these new species, and considered it likely that they, with L. angasii Baird, 

 might well be only varieties of a very widespread specie?., Lepidurus viridis. 



Tate described (Proc. Roy. Soc. S. Avst., 1878-79, p. 136) a species 

 which he called Lepidurus viridulus. I have not been able to consult this 

 paper, but probably the species is only a variety of L. viridis, being given 

 as a synonym by Sayce (1903, p. 242). 



Spencer and Hall, in their Report of the Horn Expedition to Central Aus- 

 tralia (1896, pt. ii, " Zoology," p. 234), mention Lepidurus viridis as being 

 found near the coast and not inland. 



In 1903 Sayce mentions the species in his list of Phllyopoda of Australia, 

 and gives synonyms (1903, p. 242) ; and it is again cited in Hutton's Index 

 Faunae Novae Zealandiae (1904, p. 267). 



Distribution. 



Sayce (1903, p. 242) has been followed in classing L. angasii, L. MrJcii, 

 L. compressus, and L. viridulus all as synonyms of L. viridis Baird. The 

 species, therefore, appears to be widely distributed in Australia and New 

 Zealand. 



The earliest recorded specimen, as already mentioned, was from Tas- 

 mania (Baird, 1850). Sayce (1903, p. 242) gives its distribution thus : 

 '' Inland and coastal areas of N.S.W. ; northern and southern areas of 

 Victoria ; southern area of South Australia ; Tasmania ; and New Zea- 

 land." 



The only published record of the species given in New Zealand is that 

 given by G. M. Thomson (1879, p. 260), and he gives the habitat as 

 Wellington, Waikouaiti, and Queenstown. 



In the collections of the Biological Laboratory of Canterbury College are 

 specimens received from Ashbuiton (October, 1902), Cashmere (December, 

 1904), Linwood (September, 1916), Spiingston (October, 1916). Dr. F. W. 

 Hilgendorf has found them at Lincoln, and Mr. G. E. Archey in pools near 

 New Brighton. 



Occurrence and Habits. 



Lepidurus viridis, in common with most of the Phyllopoda, is found in 

 stagnant shallow water in pools sometimes " only a few square yards in 

 area " .(Caiman, 1909, p. 161). These pools are formed by the spring rains 

 in gravel-pits or clay mudholes. Dr. Hilgendorf has found specimens of 

 Lepidurus at Lincoln in very small holes formed by the hoof of a horse or 

 cow. The sudden appearance of these animals is due to the rapid develop- 

 ment of the " winter " or " resting " eggs. Their rate of growth must be 

 very great, for Spencer and Hall (1896, p. 228) speak of collecting full- 

 grown specimens of the allied genus Apus, 2 in. or 3 in. in length, " cer- 

 tainly not more than two weeks after a fall of rain " ; and Packard (1882, 

 p. 328) speaks of Apus himalayanus, a species found in North India, as 

 being collected from a stagnant pool in a jungle, four days after a shower 



