no. 1136. OBSERVATIONS ON THE AST ACID Jl— FAXON. 660 



Astavus caldwelli Bate, Proc. Zool. Soc. Londou, 1865, p. 469, pi. xxvn. 

 Astacoidcs madagascar'unsis Huxley, Proc. Zool. Soc. London, 1878, p. 759, fig. 

 2 B ; p. 773, fig. 7; The Crayfish, p. 251, fig. 65, 1880. 



Habitat. — Madagascar. 



The only specimen of this species that I have seen is Guerin's type, 

 in the Museum of the Academy of Natural Sciences of Philadelphia 

 (No. 290, Guerin Coll.). The color in life, according to Goudot, is 

 brownish green. 



ASTACOPSIS Huxley. 



Astacopsis Huxley, Proc. Zool. Soc. London, 1878, p. 764. 

 Type, Asiacus f rank! i nil Gray. 



Rostrum triangular, concave above, margins toothed. Antennal 

 scale of moderate width, tapering off to an apical spine. Anterior 

 process of epistome long triangular. Superior border of hand deutate. 

 Carapace and abdomen more or less tuberculous or spinous, at least iu 

 mature individuals. Form homaroid. Twenty-one gills on each side 

 of the trunk, disposed as shown in the following formula: 



Arthrobranchi.®. 



Somite. Podobranchi^e. . ; — - PleuroisranchivE. 



Anterior. Posterior. 



VII. . . . O(epr) . . . . . . . . . . = 0(epr) 



VIII. ... 1 .... 1 .... .... =2 



IX. ... 1 .... 1 .... 1 .... =3 



X. ... 1 .... 1 .... 1 .... =3 



XL ... 1 .... 1 .... 1 .... 1 =4 



XII. ... 1 .... 1 .... 1 .... 1 =4 



XIII. ... 1 .... 1 .... 1 .... 1 =4 



XIV. ... .... .... .... 1 =1 



6 + epr + 6 -f- 5 + 4 = 21 + epr 



Habitat. — Australia and Tasmania. 



ASTACOPSIS FRANKLINII Gray. 



Astacus franklinii Gray, Eyre's Journals of Expeditious of Discovery into Cen- 

 tral Australia, I, p. 409, pi. in, tig. 1, 1845; List Crust. Brit. Mus., p. 72, 

 1847 (no description ). 

 Astacns franklinii Ericiison, Arch. f. Naturgesch., 12ter Jahrg., I, p. 375, 1846 

 (after Gray). 



Astacopsis franklinii Huxley, Proc. Zool. Soc. Londou, 1878, p. 764, figs. 4, 5. 



Astacopsis franklinii Harwell, Cat. Australian Stalk- and Sessile-eyed Crustacea, 

 p. 176, 1882 (after Gray). 



Habitat. — Tasmania. One specimen (male), 96 mm. long, in Museum 

 of Comparative Zoology (No. 1140), from Hobart Town, Mr. Robertson. 

 The angles of the abdominal pleime in this specimen tend to develop 

 spiny points. 



Astacopsis franklinii is similar in external appearance to the Mada- 

 gascar crayfish {Astacoides Madagascar iensis). The latter, however, as 

 has been shown by Huxley, has the number of gills reduced to twenty- 

 four, against forty-two in the former. A. franklinii appears to be rep- 



