Lucanide. 370 
central sulcus; the posterior lateral angles are obtuse, 
and slightly emarginate. It is 7} lines long, including 
the mandibles. 
From the preceding observations it would appear, that 
these Tasmanian species may be thus distinguished, so 
far as the males are concerned. 
A. Those with the posterior lateral angles of the pro- 
thorax oblique, with a prominent angle opposite 
the shoulders of the elytra. 
a. Those with the fore-margin of the prothorax 
anteriorly produced in the middle. 
* Prothorax with a small central frontal 
polished tubercle. 1. L. cancroides. 
** Prothorax with two small tubercles con- 
joined in middle of front margin of 
prothorax. 2. L. subtuberculatus. 
b. Those with the fore-margin of the prothorax 
straight; front of head strongly retuse. 
3. L. curvicornis, Latr. 
B. Those with the posterior lateral margins of the 
prothorax rounded. 
4. LD. Launceston. 
5. LL. obtusatus. 
6. (?) DL. obtusatus, var. dimidio minor, man- 
dibulis multo minoribus, dente apicali 
cum dente lato medio coalito. 
Mount Wellington, March, 1866. Dr. 
Howitt. 
Explanation of Plates. 
Puate VIII. 
Fig. 1. Nigidius Parryi (slightly magnified) ; la, maxilla; 1b, mentum ; 
1c, antenna. 
2. Dorcus ratiocinativus, g (nat. size); 2a, maxilla; 2b, mentum, 
and one of the labial palpi; 2c, terminal joints of antenna. 
3. Dorcus rudis, 2 (rather magnified); 3a, head, seen from above ; 
3b, maxilla; 3c, mentum ; 3d, labrum and labial palpi. 
