Cu2 rEOCEEDINGS OF THE NATIONAL MUSEUM. vol.xx. 



CHERAPS PREISSII Erichson. 



.htnciis (Cheraps) preissii Erichson, Arch. f. Natnrgesch., 12ter Jahrg., I, p. 



101, J846.' 

 ?A8lacoid('S pli'hcj us HKSii, Arch. f. Natuigesch., Slter Jahrg., I, p. 164, pi. vii, tig. 



17, 1865. 

 Astacus preissii von Martens, Monutsber. Akad. AVisseiisch. Berlin, 1868, p. 617 



(after Erichson). 

 Astacopsis preissii Haswell, Cat. Australian Stalk and Sessile-eyed Crust., p. 



177, 1882 (after von Martens). 



Southwestern Australia (Ericbson). Ericlison's types could not be 

 found in tlie Berlin Zoological Museum by Doctor von Martens in 1868. 

 Victoria, Australia (No. 4350, Coll. Mus. Comp. Zool., one male). 



The specimen in tlie Museum of Comparative Zoology agrees well 

 with Erichson's diagnosis, so far as it goes. It shows alow i)ostorbital 

 ridge on each side of the gastric area, terminating anteriorly in a 

 minute blunt tubercle. The rostrum is flat and punctate, lightly margi- 

 nate, the margins passing anteriorly into the short, triangular acumen 

 without developing lateral spines or teeth. The areola is mucli broader 

 than in C. hicarinatus, measuring 5.5 mm. in width (length of the whole 

 animal, 109 mm.). The outer part of the upper surface of the hand is 

 thickly sown with very large, deep pits. The fingers are strongly 

 curved, the movable one armed within with a large, blunt tooth. The 

 carpus bears a long and stout tubercle on its inner border; this tuber- 

 cle is curved forward and is blunt at the end; there are, besides, a few 

 low tubercles on the anterior border of the lower face of the carpus. 

 The anterior process of the epistoma is bounded behind by a slight 

 transverse furrow ; its sides are very convex, and its anterior angle is 

 produced so as to form a thin, vertical plate. 



Hess's Astaco'ides plebejiis came from Sydney, New South Wales. 

 The shape of the large chehe,the breadth of the areola, and the color (yel- 

 lowish, the large claw\s dusky) make it i^robablethat this si^ecimen was 

 Cheraps preissii. The specimen (dry) of C. preissii in the IMuseum of 

 Comparative Zoology has chelipeds of a very dark purplish color, in 

 striking contrast with the yellow hue of the rest of the body. It is true 

 tliat the dee]>, large pits seen on the chehe of C. preissii are ignored in 

 both the description and the figure of Astaco'ides plebejits, and that the 

 telson has a very ditt'erent shape, if Hess's figure be correctly drawn. 

 Ortmann treats Astaco'ides plehejus as a synonym of Cheraps preissii, 

 but I think that Ortmann's sx)ecimen of C. preissii was in reality C. 

 bicarinatiis. (See l)elow\) 



CHERAPS BICARINATUS (Gray). 



Astacus bicaniialiis Gray, Eyre's .Journals of Expeditious of Discovery into 

 Central Australia, I, p. 410, pi. in, tig. 2, 1845; List Crust. Brit. Mus., p. 72, 

 1847 (no description). 



Astacus Mcarinatus Erichson, Arch. f. Katurgesch., 12ter Jahrg., I, p. 376, 1846 

 (after Gray). 



