50 NOTES ON TASMANIAN CETJSTACEA, ETC. 



distinct epimeral tliickeiiings on the sides of tlie abdominal 

 segments. The legs of the second to the fifth pairs are 

 destitute of spines, but have the carpus, propodos, and 

 especially the dactylos somewhat thickly furnished with hairs. 

 The tehon (fig. 5) is short, very broadly rounded, and is 

 thinly membranous in texture. The external plate of the 

 last pair of pleopoda broadens posteriorly, and is strengthened 

 by two stout nearly parallel median ridges in addition to its 

 marginal thickening ; the internal plate is obliquely fan- 

 shaped, and is strengthened by one median ridge. Length 

 44 mm. (If inch) . 



A single specimen was handed to me by Mr. A. Simson 

 (after whom the species is named), who obtained it on the 

 East Coast. It is a female, having the whole under surface 

 of the abdomen covered with ova. 



Earn. Astacidx. 



4. Astacojjsis frariJcliriii. Gray. 



A few small specimens of this common freshwater Crayfish, 

 obtained at Zeehan (?), were handed me by Mr. Simson. 

 Gray's short description reproduced in the Australian 

 Museum Catalogue (p. 176) is substantially accurate. la 

 none of my specimens, however, were " the sides of the 

 second abdominal rings sj^inose." On all of them examples of 

 the parasitic Temnoceplialus qudricornis (Haswell) were 

 found. 



6. EngcBUS cunicularius. Erichson (PL I., figs. 1 and 2). 



Specimens of this small freshwater crayfish, collected at 

 Zeehan (?), were handed me by Mr. A. Simson. The name 

 is wrongly printed E. cunicularis in the Australian Mus. 

 Cat. It differs from E. fossor, according to Erichson 

 (Archiv fur Naturg., 1846, p. 102) not only in the absence 

 of a toothed border on the lower side of the hand, but also in 

 its more rounded carapace, its broader rostrum, larger eyes, 

 sharp-pointed antennary scale, and in the greater breadth of 

 the posterior part of the abdomen. In the absence of 

 examples of j&./ossor, I cannot compare the two forms, but 

 the characters seem hardly good enough to found a specific 

 distinction upon. 



My largest specimen was If inches in length from the point 

 of the rostrum to the extremity of the caudle swimmerets ; 

 the chelae were about 1| inches long. In the figure (fig. 1) the 

 relative narrowness of the abdominal segments as compared 

 to the carapace is not brought out. The carapace is deep 

 relatively to its breadth, and in general appearance the whole 

 body is much compressed, The carapace is produced in front 

 into a minute sharp rostrum (fig. 2), reaching slightly beyond 



