REPORT ON THE CRUSTACEA MACR,URA. 107 



embodied in Eyre's Journal of Expeditious of Discovery in Australia (vol. i. p. 409, 1845), 

 as " a large species living in the said river (Murray), weighing about two pounds, and 

 possessing the same flavour as the European lobster." Dana records his Astacopsis 

 (Astacoides) nobilis from New South Wales, with a query attached. 



The carapace is one-half the length of the animal, anteriorly produced to a short rostrum 

 that tapers to a sharp-pointed depressed tooth, on each side of which posteriorly are 

 three distinct teeth that gradually lessen in size and then fade away leaving only 

 rudimentary traces of denticulation. The ridge on which these teeth stand increases in 

 size as the teeth diminish to a short distance behind the orbital margin. Between these 

 ridges the median surface of the rostrum is depressed and forms a longitudinal groove 

 that fades away on the gastric region. On each side of the base of the rostrum, posterior 

 to the orbit, is a longitudinal tooth, but slightly projecting to a point, and grooved in 

 its entire length, behind which another small cusp-like tooth projects anteriorly from a 

 low tubercle. Lateral to the preceding, on the hepatic region, are four sharp strong teeth 

 on one side, while on the other some of them are reduced to small tubercles. The dorsal 

 surface of the carapace is smooth and almost polished on the gastric region, which is 

 separated from the cardiac by a deep cervical sulcus. The dorsal surface of the cardiac 

 region is smooth and separated from the branchial regions by a longitudinal furrow 

 that traverses the dorsal surface from the cervical sulcus to a short distance from the 

 posterior margin of the carapace. The whole of the branchial region is evenly 

 covered with small tubercles, the upper portion being armed with two rows of large 

 and prominent tubercles, the dorsal row having the appearance of being much worn 

 down ; near the anterior extremity of the branchial region, just behind the lateral 

 portion of the cervical groove, are four or five rather long and sharp-pointed teeth. 



The pleon has the anterior portion of each somite, depressed and the posterior 

 elevated ; the dorsal surface is smooth in the median line, and is flanked on each side 

 with a row of large tubercles, one to each somite, that on the fifth being the smallest and 

 most pointed ; on each side, standing on the coxal plates, is a series of long and strong 

 spine-like teeth that are directed vertically from their base. 



The first somite carries no appendage, consequently the coxal plate is wanting, and a 

 single tooth stands near the margin. 



The second somite has one large tooth standing near the middle of the lateral margin 

 of the somite, and five others, smaller but still large teeth, in a line lying a little within 

 the margin of the coxal plate. 



The three following somites are armed with a large tooth near the centre of the 

 lateral margin, and two below it, one above the other, in the median line. 



The sixth somite has a bunch of five smaller teeth on each side of the narrow, smooth, 

 median dorsal surface. 



