248 MARSHALL: ADDITIONS TO 'BRITISH CONCHOLOGY. 



be more triangular in outline, the shell being longer and 

 the beaks more central and acute. 



Saxicava rugosa van cylindrica S. Wood. Extremely 

 broad one way and narrow the other, of an equal depth 

 throughout, corresponding to a similar variety of Mya 

 hhighami. I have met with this at Guernsey, Land's End, 

 Torbay, and Lamlash, but it doubtless occurs in other 

 places. Its peculiar cylindrical shape is caused by occupy- 

 ing the deserted tubes of serpulas. Malm has also found 

 it 'in the burrows of Limnoria lignorum' (' B. C.,' vol. ii.) 

 Searles Wood described it from the Red Crag. 

 The variety miin/fa should be expunged from the list. It 



is synonymous with the var. ardica. 



Teredo megotara var. subericola Jeff. Described by 

 Jeffreys as T. subericola in the 'Annals' for August, i860, 

 but afterwards identified as a dwarf form of T. megotara. 

 It lives exclusively in floating pieces of cork, and is 

 sufficiently remarkable to be retained as a variety. (See 

 'B. C.,' vol. iii., pp. 178—9-) 



Cadulus Jeffreys! Monte. The species described by Dr. 

 Jeffreys as C. suhfusiformis in the Appendix to ' British 

 Conchology ' was afterwards stated by the Marquis de 

 Monterosato to be not that species, and he re-named it 

 Helonyx jeffreysi. Cadulus of Philippi is, however, prior 

 to Helonyx of Stimpson, and the former generic name 

 prevails. On searching over his specimens Dr. Jeffreys 

 found one C. suhfusiformis, however, and although a single 

 specimen is a slender claim to rank as a British species, 

 there is no doubt that both live together, and will be 

 found in the locality indicated. Dr. Jeffreys dredged 

 Cadulus only once, when they came up rather plentifully. 

 C. jeffreysi has also been dredged in the 'Porcupine' 

 cruise in the Shetlands and off Valentia. 



Chiton scabridus Jeff. (For description of animal and 

 shell see the 'Annals' for July, 1880.) I found this 



J.C, vii., Oct. 1893. 



