19 



NOTE ON MYRINA SIMPSONI, MARSH. 



By J. T. MARSHALL. 



With reference to my paper describing this species^, I am indebted 

 to Mr. Edgar A. Smith for pointing out to me that he " understands 

 the name Myrina, H. and A. Adams, was preoccupied many years 

 ago, but does not see how it is conchologically separable from Adula 

 of the same authors." I do not know the genus Adula, but my faith 

 in Mr. Smith's conchological instinct is so strong that I have no hesi- 

 tation in substituting Adida, H. and A. Ad., for Myrina. 



Mr. Smith also writes me that Adula (Myrina) pelagica, the type 

 of the genus, was found "off the Cape of Good Hope, attached to 

 floating masses of blubber." 



Since my paper on the subject appeared in this journal, a piece 

 of pitch pine, bored by Xylophaga and Teredo, was landed on the 

 nsh-quay of Aberdeen by a trawler, who said it came from the 

 " Shetland fishing-grounds," and in the deserted tubes were Adida 

 simpsoni attached by a byssus. This is especially interesting, as the 

 habitat is in complete harmony with that of A. argenteus, Jeffr., 

 from frigid water in the Shetland-Faroe Channel. It is probably owing 

 to this concealed habitat that the present specimens are much paler 

 than those originally described. About two dozen specimens were 

 obtained on this occasion, several of which were still alive, and were 

 placed under examination. " They were quite at home in a watch- 

 glass, and travelled by first protruding the foot, and then by con- 

 tracting it drew the shell along," while under the microscope " the 

 action of the current through the tubes could be seen through the 

 valves of the shell." (Mr. J. Simpson iii litt.) 



A specimen sent me in spirit yielded the following results, which 

 demonstrates that the animal is not far removed from Modiolaria : — 

 Body dirty white, viscera light brown ; mantle free, plain ; incurrent 

 tube formed by the two flaps of the mantle ; excurrent tube short, 

 thick, and conical ; foot large, white, and tongue-shaped, with a 

 conspicuous groove down the centre for the byssus. 



At the time of writing another whale's skull has been landed at 

 Aberdeen by a local trawler, which was brought up " 20 miles N.W. 

 of Fair Isle " (between the Orkneys and Shetlands), to which two or 

 three dozen A. simpsoni were attached. 



I Journ. Malac, igoo, vol. vii, p. 167. 



