FRESHWATER AND LAND CRAYFISHES OF AUSTRALIA 
37 
sharp spine and a small blunt spine on upper margin of carpus ; merus with 
one large and four small sharp spines on upper margin. 
Habitat. Tasmania: Lake St. Clair (type locality) (Spencer, 1893); 
Cradle Mountain. 
Types in the National Museum, Melbourne. 
This species was identified by Smith as A. franklinii var. 
tasmanicus Er., and is mentioned in his notes on that species. 
As shown elsewhere in this paper tasmanicus Erichson is not 
an Astacopsis. A. tricornis differs from other species of the 
genus in having the rostral carinae produced into long blunt 
spines, giving the impression of a pair of horns ; also by the 
openings under the lateral processes of the sternal keel. 
Five specimens examined. 
Genus ENGAEUS Erichson. 
Astacus ( Engaeus ) Erichson, Arch. f. Naturg., xii, 1846, p. 102. 
Astacus von Martens, Monats. Akad. Wiss. Berlin, p. 618, 1868. 
Engaeus Huxley, Proc. Zool. Soc. Lond., p. 769, 1878; Haswell, Cat. 
Austrl. Mus., Crust., p. 178, 1882; Faxon, Proc. U.S. Nat. Mus., 
xx, p. 670, 1898; Faxon, Mem. Mus. Comp. Zook, xl, 8, p. 403, 
1914; Smith and Schuster, Proc. Zook Soc. Lond., 1913, p. 118. 
Carapace higher than broad, punctate or feebly tuberculate, cervical groove 
either feeble or moderately well impressed, somewhat “V” shaped. Rostral 
carinae smooth or feebly tuberculate. 
Abdomen smooth, punctate, or setose; lateral margins rounded. First 
somite without lateral lobes. Telson without transverse sutures, entirely 
calcareous. 
Second antennae set under the first ; squames small. Upper lip short and 
broad, and more or less highly arched medianly. 
Sternal keel narrow, posterior pair of lateral processes large and deeply 
grooved. Vas deferens on simple short papillae on coxae of fourth pereo- 
pods. 
Stems of podobranchs without wing-like expansions. Posterior pleuro- 
branchs usually well developed, sometimes rudimentary. Gill formula 
21 + epr. 
Genotype Astacus (Engaeus) fossor Erichson. 
Key to Species of ENGAEUS Erichson. 
Abdomen longer than carapace. Sternal keel without openings on lateral 
processes. 
Cervical groove moderately impressed, areola broad. 
Uropods rounded. 
Great chelae slender, a row of feeble tubercles on upper margin, lower 
margin smooth CUNICULARIUS Erich. 
Abdomen as long as carapace. Sternal keel with openings on lateral processes. 
Cervical groove deeply impressed ; areola fairly broad. Uropods pointed. 
Great chelae with a row of tubercles on upper, lower and posterior 
margins PHYLLOCERCUS Sm. and Sch. 
