ANASPIDACEA I I 



the anterior thoracic region. The auditory organ is at the base 

 of the first antennae. 



Order. Anaspidacea. 



Fam. 1. Anaspididae. The mountain -shrimp of Tasmania, 

 Anaspides tasmaniae, was first described by Thomson l in 18!."> 

 from specimens taken in a little pool near the summit of Mount: 

 Wellington ; it was redescribed by Caiman, 2 who* drew attention 

 to its remarkable resemblance to certain Carboniferous fossils of 

 Europe and X. America (Gamp so nyx, Pcdaeocaris, etc.). 



The creature appears to be confined to the deep pools of tin- 

 rivers and tarns on the mountains of the southern and western 

 portions of Tasmania. 3 The waters in which it occurs are always 

 cold and absolutely clear, and there is no record of its living at 

 altitudes much below 2000 feet, while it frequently occurs ;it 

 4000 feet. The body may attain upwards of two inches in 

 length ; it is deeply pigmented with black chromatophores, and 

 it is held perfectly horizontal without any flexure. The animal 

 rarely swims unless disturbed, usually walking about on stones 

 and water-plants at the bottom of deep pools. In walking the 

 endopodites of the thoracic limbs are chiefly instrumental, but 

 they are assisted by the exopodites of the abdominal limbs. 



When frightened the shrimp can dart rapidly fonvards 

 or sideways by the strokes of its powerful tail-fan, but it never 

 jumps backwards as do the other Malacostraca. It appears t<> 

 browse, upon the algal slime covering the rocks and on the 

 submerged liver-worts and mosses, but it does not refuse animal 

 food, even feeding on the dead bodies of members of its own 

 species. The thoracic limbs, which are all biramoits except tin- 

 last pair, Carry a double series of remarkable plate-like gills on 

 their coxopodiles. The slender and setose exopodiles of t In- 

 thoracic limbs are respiratory in function, being kept in continual 

 motion even when the animal is at rest, and serving to keep ii|> a 

 current of fresh water round the id" s - 



AnHjn'<ti'x shows a remarkable combination of structural 

 characters, some of which are peculiar, while others are possessed 

 in common with the iVrac.arnla or Kucarida. The chief peculiar 



1 Trans. Linn. Soe. 2), vi., 1894 L897, p. !-'>.'>. 



- Trims, /tni/. Soc. l-'.'i'iiil'in-'tfi, xxxviii., 1M'7. ) 7-; 



:; G. Smith, Proc. Roy. Soc 1908. 



