MARSHALL : ADDITIONS TO " BRITISH CONCHOLOGY." 293 



true he had the specimens from me, but their origin was Jersey. 

 O. brevicula Mtros. {non Jeffr.) I consider a dwarf and deep-water 

 form of this variety. 



Var. moulinsiana Fisch. (/. Cojich., vol. 7, p. 381, 1893) — 

 The colour of this variety is yellowish-white ; length o - i5 in., breadth 

 0*04. This cannot be confused with any other form, and once seen 

 is easily identified. It has the proportions of O. fenestraia, with very 

 coarse sculpture and a prominent tooth. 



Var. suturalis Phil. — In this variety the last whorl does not 

 project beyond the penultimate one, or is sometimes narrower, with a 

 contracted mouth and a base more or less keeled. Length o - i inch, 

 breadth 0*03 inch. The var. suturalis of "British Conchology" is 

 the form described and figured by Philippi as var. gracilis, which I 

 regard as only another form of his var. suturalis ; but as a matter of 

 fact the true var. suturalis of Philippi does not occur on our coasts. 

 Our form is almost cylindrical, with sculpture of every degree from 

 fine to coarse, common, and generally diffused. 



None of the published figures in British works are correct, and no 

 two agree with each other, which is not surprising considering its 

 extreme variability and that each writer takes a different form for his 

 type. Jeffreys' figure is the type form ("conic oblong"); Sowerby's is 

 too narrow and compressed, the tooth too prominent, and the mouth 

 too wide; and both these figures err in depicting spiral striae through- 

 out the shell, instead of one or two lines only at the base of each 

 whorl; while Forbes and Hanley figure a conical shell, without any 

 interstitial stria? at all. G. O. Sars 1 gives one good figure of the type 

 (t. 22, fig; 14), but a second figure (t. 14, fig. 2) does not represent it. 



Gwyn Jeffreys was too hasty in combining various Continental 

 varieties as synonyms of each other, yet at the same time adding 

 another of his own (var. multicostata), besides accepting another as a 

 species (0. Jeffrey si) and adding still another to that species (var. 

 flexicostd). They all have the same specific sculpture, it is true, 

 though varying in infinite degrees, and so indicating varieties of one 

 species; but their very distinct outlines and proportions merit varietal 

 names. Some Continental writers go so far as to name all the forms 

 distinct species, which is erring on the other side; and of course in 

 this, as in many others, it is confusing to deal with them in writing, 

 for what British writers are accustomed to regard as individual or 

 sexual differences they consider varieties, varieties they consider 

 species, species as genera, &c. It is promotion all round, or, as one 

 writer has satirically observed, "regiments in which all the members 

 are officers." Of O. interstincta Jeffreys has written : — "This abundant 



1 Moll. Regionis Arctica; Norvegiae. 



