336 JOURNAL OF CONCHOLOGY, VOL. 9, NO. II, JULY, I9OO. 



Var. obeliscus Jeffr. — Guernsey, 18 f. ; Scilly, 40 f. ; Eddystone, 

 30 {.; Glenelg, 30-60 f. ; the Minch, 50 f. This is a rare form in 

 Britain. It resembles Eulima in the flattening of the whorls and fine 

 sutural lines. Plenty of typical specimens equally resemble Eulima 

 in these respects, but this is a small and slender cylinder. Jeffreys' 

 original figure 1 is not compressed enough, but more nearly represents 

 a half-grown type shell. It is less rare in extra-British waters as 

 Eulimella subcylindrata Dunk. (1862). 



O. acicula is one of the most variable species of the genus, em- 

 bracing every variation of shape, size, and compression. Out of one 

 hundred specimens taken haphazard, not more than twenty will be 

 found to conform to the type. Some have a shallow suture and 

 angulated base, and look like a slender O. scillce. Many are obtusely 

 keeled, and some have the top whorls abruptly ending as in O. 

 innovata. Others (from Guernsey and Scilly especially) have the 

 whorls as rounded as O. ventricosa, and give some trouble in 

 differentiating from that species. A good microscopic character, when 

 the shells are fresh, is that O. ventricosa is quite smooth, while O. 

 acicula is spirally striated throughout, as in O. scillce and O. nitidis sima, 

 and these striae can be seen with a Coddington lens. Extra-British 

 forms of both species are much more distinct. A slender dwarf 

 variety peculiar to Guernsey is distinct from any of the named 

 varieties, and another from Scilly, more slender still, is equally 

 distinct. I have besides eight other varietal forms from various parts 

 of the British coasts. The largest come from Guernsey and the 

 Shetlands, and measure two lines by one-half, and it is more plentiful 

 in the former district than elsewhere. I have several deep-water 

 specimens from the Mediterranean which are very deceptive in having 

 all the appearances of a ribbed shell. These ribs are broad and flat, 

 with interstices of the same width, and are continued with great 

 regularity sometimes throughout the entire spire or on the lower whorls 

 only ; but these ribs are caused by frequent and methodical starts of 

 growth of the animal, which alter the whole aspect of the shell, and 

 make them resemble Turbonillcz rather than Eulimellce. 



Jeffreys' figure is a good one, but perhaps too slender in proportion 

 to length. Forbes and Hanley give two figures, both of which are 

 too broad at the base. Sowerby's is unlike ; it represents a conical 

 shell with a sharp apex, and the dimensions are too small. 



Monterosato 2 substitutes E. commutata for this species, on the 

 ground that Auricula acicula Lamk. = 6 > . acicula Desh., are Eulimella 

 of the Paris basin ; but vide Jeffreys 3 on this point. 



1 Ann. Mag. Nat. Hist., ser. 3, vol. 1, p. 46, pi. ii., f. Si 1858. 



2 Nomenclatura Gen. e Sp. Conch. Med., p. 98. 



3 Moll. "Lightning" and "Porcupine," Proc. Zool. Sac, 1884, p. 362. 



