MARSHALI: : ADDITIONS TO " BRITISH CONCHOLOGY." 185 



taken the Montacutce, I have never met with a specimen of the Lepton 

 or Gebia. My use of the term " byssal threads " in the paper above 

 cited (pp. 400 and 402) did not mean byssi of the same nature as 

 that of Mytilus, etc. It would, perhaps, be more correct to describe 

 them as "glairy threads." 



A remarkable specimen from the Scillies, dredged in 4of , looks at 

 first sight like a new species. It is double the size of the type, more 

 solid, and underneath the hinge-plate, about a line from the beaks 

 and almost hidden from view, is a small pearl-like tooth in each 

 valve on the anterior side. Perhaps these latter may be accidental 

 excrescences, but outwardly the shell is more strikingly different, 

 each valve being rayed with shallow corrugations from the beaks to 

 the margins, somewhat after the manner of var. nivea G. O. Sars,' 

 which he describes as " radiatum striolate." 



var. oblonga Turt. — Very local. Off Loch Ryan 2^i., Clyde 

 i8f. 



M. donacina S. Wood. — Church Bay, Antrim, two valves 

 (Chaster). 



M. dawsoni Jeff. — A dwarf and obliquely-triangular variety of 

 L. clarkice was mistakenly recorded by me as M. daivsoni from 

 Scilly, Torbay, Bantry Bay, and Bartra Island.-^ They have a close 

 resemblance outwardly, and are, indeed, indistinguishable, but an 

 examination of the hinge reveals the dentition of L. clarkice. My 

 only reliable records for M. daivsoni are one valve from Killala Bay, 

 and five from West Orkneys. It is evidently variable, because both 

 the preceding are different in outline from the Donegal Bay form 

 dredged by the 'Porcupine,' which again is different from the Arctic 

 form. 



M. (Decipula) ovata Jeff. — I do not consider the hinge of 

 Decipida Jeff, to be -" generically different" from that of Montacuhi 

 Turt., but that the name should be relegated, equally with Telltmya 

 Brown, to synonyms of Mofttacuta. 



A few small valves, which I have not seen, were said to have been 

 dredged at Scariff in 4of., Great Skellig 48f., and off Baltimore 3of., 

 all in the south-west of Ireland, during the Royal Irish Academy 

 cruise of 1885. 



Kellia SUborbicularis Mont.— Rock-pools on the Kincardineshire 

 coast, among the roots of zoophytes (Simpson)! 



Kelliella miliaris Phil, has been dredged off the Shetlands in in f., 

 and between the Shetlands and Norway in i^'ji. (Simpson) ! 



Tellhitya nivea G. O. Sars, Moll. Reg. Arct. Norv:,p. 71, tab. 20, figs. 2 a-c. 

 Journ. 0/ Conch., 1S97, vol. viii., p. 350. 



