MOLLUSCA FROM ONE HUNDRED FATHOMS, 

 SEVEN MILES EAST OF CAPE PILLAR, TASMANIA, 



By C. Hedley, Conchologist, and W. L. May. 



(Plates xxii-xxv.) 



No vessel equipped for deep sea investigation like the 

 " Challenger " has ever explored the Tasmanian coast. The 

 nearest point where a deep sea dredge has been hauled is oft* 

 Twofold Bay, about four hundred miles from the scene of our 

 work. Hitherto Tasmanian naturalists have confined their 

 attention to shallow and sheltered waters. 



To search further and deeper the writers engaged the "Sea- 

 Bird," a serviceable steamer of twenty-tive tons, and spent some 

 hours of December 17th and 18th, 1907, in dredging around a 

 spot seven miles east of Cape Pillar in an estimated depth of 

 one hundred fathoms. We enjoyed the company and assistance 

 of Dr. J. C. Elkington during the cruise. The weather was 

 rough and unpleasant, and the success attained was due to the 

 skilful management of the apparatus by the ship's engineer, Mr. 

 Gulliver. We employed the bucket dredge, and for the final 

 haul trailed a dredge behind the bucket with excellent results. 



The submarine slope of the land is here extremely steep. The 

 contour has not been fully developed by soundings, but the 

 few scattered observations indicate that a depth of three hundred 

 and forty-three fathoms is reached about eight miles from the 

 laud, descending to over a thousand fathoms at twelve miles and 

 the level floor of the abyss, two thousand two hundred and seventy 

 five fathoms beneath the surface, is attained at a distance of 

 seventy miles. 



A remarkable feature was the total absence of mud in the area 

 examined. The hard ground diminished the proportion of 

 bivalves to gasteropods. The sea-floor was shown by the dredge 

 to be carpeted by a dense growth of tunicates, alcyonaria, sponges, 

 lnyozoa, etc., on a firm bottom of sand, rolled pebbles, and a 

 conglomerate of recent shells. The rock was hard enough to dint 

 the lip of the bucket. Some specimens of the siliceous pebbles, 

 quartz, chert, jasper, etc., which Dr. C. Anderson kindly weighed 

 for us, were 1092, 0'774, and - 509 grams respectively- The 

 coral Flabellum australe, Moseley, was abundant, and reached a 

 large size. While we worked, a strong current drifted us north- 



