bV c. hedley. 701 



Chemnitz remained unrecognised. Lamarck seems not to have 

 distinguished between this and its Tasmanian representative, 

 which he called Monodonta constricta. Under his influence, 

 Quoy &, Gaimard figured for constricta in the zoology of the 

 Astrolabe, both the Sydney "zebra" (Plate 63, figs.23-24), and 

 the Hobart "trochlea" (figs.26, 27). This error had a long 

 existence, for these two were still united in 1902 by Pritchard 

 & Gatliff. But Quoy & Gaimai-d, in partial recognition of their 

 mistake, submitted Trochus treniatus as a name for the Port 

 Jackson species. This name is not to be confused with Turbo 

 tceniatus Sowerby (Tankerv. Cat., 1825, Append., p.xiii.). Chenu 

 twenty-five years afterwards, added another name, Trochocochlea 

 multicarinata. Morch then pointed out that the names of these 

 Parisian conchologists were anticipated by Monodonta zebra of 

 Menke: a name not to be confused with Trochus zebra Wood 

 (Index Test., 1828, Suppl., PI. v., fig.l8). For this already over- 

 burdened species, Arthur Adams proposed Labio porcatus, and 

 Fischer, to avoid clashing with Trochus porcatus Philippi, (Zeit f . 

 Malak., 1849, p. 187) gave the final name of Trochus extenuatus. 



Guided by a suggestion in Pilsbry's Monograph, I forwarded 

 a series from this coast, and requested Dr. H. Lynge to compare 

 them with the type of T. obtusits still preserved in the Zoological 

 Museum of Copenhagen. That conchologist kindly replied 

 (30/4/16) that the worn and injured shell, which Chemnitz figured 

 in 1795, is absolutely identical with the specimens I sent from 

 Montagu Island. 



The species has a great range in colour, development of spiral 

 keels, form and size. Typical M. obtusa is a rather depressed 

 form, with 30-40 close, narrow lines; this intergrades with a 

 more abundant, broadly-banded form, ce6rrt, with about ten 

 stripes, and with a dwarfed variety from the border of the 

 mangrove-swamps which can be called porcata. The species 

 ranges from Moreton Bay to Twofold Bay; its southern limit is 

 not known to me. 



Another Monodonta occurring in this State is M. concamerata 

 Wood, 1828( = Trochus striolatus Quoy <fe Gaimai"d,1834, — Labio 

 fuliginea A. Adams, 1853). I have not myself gathei^ed this 



