212 Mr. F. P. Marrat on some new Species of Oliva. 
amongst other instances, to a great number of Dipterous genera 
the larvee of which wallow in the excess of their food, and 
mentions that, out of 403 species of these Diptera, Meigen knew 
only the females of 255. But these examples cannot be 
adduced as in the least in favour of Landois’s theory; for 
Meigen, in his well-known ‘ Systematische Beschreibung der 
europiiischen zweifliigeligen Insekten,’ very frequently, by his 
own admission, had only a single female and also very often 
only a séngle male in his hands as the type of the descriptions 
of his species. Such scanty material as this is certainly 
insufficient to prove the predominance of one sex over the 
other. 
XXII.—On some new Species of Oliva. 
By F. P. Marrat. 
IN selecting the following shells and describing them as new 
species, | have been guided principally by prominent features 
in each case, that, in my opinion, warrant the selection and 
publication. 
Oliva lignaria, Marrat, is very remarkable: at one time I 
supposed it might be a variety of O. ¢nflata, Lam. ; at another 
its resemblance to O. maura, Lam., appeared to be considera- 
ble; and at a third it was, until compared, thought to be a 
variety of O. irisans, Lam. It may prove to be a variety of any 
one of these three shells when specimens are obtained show- 
ing the gradual variation; but at present a shell possessing 
such connecting characters is still to be brought under notice. 
O. sabulosa, Marrat.—The specimens of this shell are de- 
scribed as having red-brown markings. I think, in most if 
not in all cases, the original colour has been dark brown, and 
that bleaching in the sun has produced the red-brown colour, 
notwithstanding one of the shells is brilliantly polished and 
possesses all the appearance of a dredged shell. 
IT am much surprised that a shell of rather common occur- 
rence and so decidedly distinct as O. angustata, Marrat, should 
have remained so long unnoticed by conchologists. Years 
ago its form was familiar to me among the shells imported in 
the boxes from China. 
1. Oliva lignaria, Marrat. 
Shell cylindrically oblong; spire depressed, callous; suture- 
edge dotted; colour drab, with dark-brown interrupted 
bands and angular lines, shaded with purplish spots and 
dotted lines ; the whole interior of the aperture of a uniform 
purple brown ; folds very prominent, one or two tinged 
