BV C. HEDLEV. 505 



A Moreton Bay oystermau once told me that when lying on the 

 floor of his craft, on a still summer night, he could distinctly hear 

 the cobra gnawing in her planks. 



As confirming this observation, Mr. C. W. Darley has kindly 

 drawn my attention to Mr. Lamb's statement, Trans. Am. Soc. 

 Civil Engineers, Feb. 1894, Vol. xxxi. p. 239. "On still summer 

 nights I have heard them grinding their way into the wood, and 

 the noise of their grinding would surprise you if you should put 

 your ear to the head of a pile in which they were at work." 



EXPLANATION OF PLATE. 



Fig. L — Exterior of right valve of T. tdci.v enlirged ; sculpture of antero- 

 median area magnified. 



Fig. 2. — Interior of the same. 



Fig. 3. — Anterior aspect of valves of T. edax in apposition ; natural size. 

 Type. 



Fig. 4. — Tube, broken to show concamerated structure, of T. edax. ; natural 

 size. 



Fig. 5. — Palette of T. edax ; enlarged. 



Figs. 6 and 7. — Interior and exterior aspects of imperfect right valve of 

 type specimen of T. antarctica, Hutton. Sculpture of antero- 

 median area magnified. 



35 



