RECORDS OF V/.A. MUSEUM. 
[229 
CHERAPS, Erichson. 
Cheraps, Erichson, Arch, fur Naturg., XII. i., 1846, p. loi. Von Martens, 
Monastb. Ak. Wiss. Berlin, 1868 (1869), p. 616. 
Chaeraps, Smith, Proc, Zool. Soc,, 1912, p. 165. 
(Not Cheraps, Huxley. Proc. Zool. Soc., 1878 (1879), p. 768.) 
The genus Cheraps was first defined by Erichson as a sub-genus 
of Astacus, Milne Edwards, for his C. preissii, but his definition 
does not include some of the most important characters by which 
the several genera of the family Parastacidae are distinguished. 
Huxley, in 1868, raised it to the rank of a genus, and described 
the branchial structures in detail, but he only had a specimen from 
the Yarra River, Victoria, which he could not, with certainty, 
identify as a true Cheraps. Taking into consideration Smith’s 
recent investigations on the Crayfishes of Australia, it is almost 
certain that Huxley’s specimen was Astacus bicariiiatiis, Gray, which 
Smith made the type of his Parachaeraps. Therefore, Cheraps of 
Huxley, but not of Erichson, is identical with Parachaeraps. 
Smith has again defined Cheraps, his definition being based on 
C. quiiiqiiecarinatus, Gray, C. teuuimanus. Smith, C. quadricarinatas, 
Von Martens, and C. intermedius, Smith, but unless these can be 
shown to be generically identical with the lost C. preissii, their claim 
to inclusion in Cheraps cannot be proved. For reasons given below, 
however I regard C. intermedins as scynonymous veith. C. preissii ; 
this conclusion be accepted, it follows that Smith’s definition 
correctly applies to Cheraps, Erichson. 
CHERAPS PREISSII, Erichson. 
Astacus (Cheraps) preissii, Erichson, Arch, fur Naturg., XII. i., 1846, p. loi. Id., 
Von Martens, Monatsbr. Ak. Wiss. Berlin, 1868 (1869), 
p. 617. 
Astacopsis preissii, Haswell, Cat. Austr. Crust., 1882, p. 177. 
Chaeraps intermedins. Smith, Proc. Zool. Soc., 1912, p, 168, pi. XXIV., fig. 2, and 
pi. XXVII.. fig. 34. 
C. preissii was very imperfectly described from a specimen 
taken in South-Western Australia and has not again been recog- 
nised. ^ This unique specimen is apparently lost since Dr. Von 
t I consider the specimens from Victoria which Ortmann (Zool. Jahrb. VI., 
1891, p. 8, pi. I., fig. I.) identified as C. preissii to be almost certainly Parachaeraps 
bicarinaitis, since it is improbable that a species occurring in the fresh waters of 
South-western Australia would also be found in Victorian rivers. Some notes 
on the distribution of P. bicarinatus, are given under the heading of that species. 
