Vol. 54.] MISS J. DONALD ON THE GENUS ACLISINA. 69 



stone Series (d^) at Glencart and at Gare near Carluke. Dr. Hunter- 

 Selkirk and Dr. Young have specimens in their collections from the 

 former locality, and I also have some given me by Dr. Young, one 

 of which is figured (PI. TV, fig. 2) ; it has nine whorls preserved, 

 and its length =3 mm., width =|- mm. 



AcLisiNA AcicuLATA, sp. nov. (PI. lY, figs. 4-6.) 



Description. — Shell slender, very elongated, composed of about 

 fifteen gradually-increasing whorls. Whorls convex, the lower 

 two-thirds ornamented by four or five sharp raised threads ; the 

 lowest of these threads appears just above the suture on the anterior 

 part of the spire, but is hidden on the posterior part ; there is some- 

 times an additional fine thread below on the body- whorl, and also 

 one above just below the suture. The spaces vary slightly in width 

 on different individuals : on some the widest is that between the 

 third and fourth threads, on others it is between the fourth and 

 fifth, while on others again the three lower spaces are nearly equal 

 and the uppermost is narrower. Lines of growth sigmoidal and 

 very oblique. Sutures deep. Aperture rounded, inner lip reflected 

 on the body-whorl. Columella nearly straight, slightly thickened. 

 Base convex, imperforate. 



Resemblances. — From A. costatula this species is distinguished by 

 its very attenuated form, by the greater convexity of the whorls, 

 and by the ornamenting threads being finer and sharper. A young 

 specimen (PI. lY, figs. 6 a, h &> c) having the protoconch entire is so 

 much worn that it is impossible to state whether it should be 

 referred to this species or to A. costatula-. The protoconch is more 

 orbicular and less inclined than that of the only example of A. cos- 

 tatula with which I am acquainted, but it does not diff'er from it more 

 than different specimens of A. pulchra var. tenuis from each other. 

 A. aciculata also resembles the Devonian species A. longissima, 

 Whidborne, in its slender form, but the threads are not so evenly 

 disposed over the surface of the whorl. I am uncertain whether 

 some very elongated shells from Law collected by Mr. Bennie 

 should be identified with this species or not ; the whorls are rather 

 more angular, and there are only four threads visible on them, with 

 nearly equal spaces between, and a very fine thread below on the 

 base ; but I place them with it for the present. One consists of 

 thirteen whorls, whose length =4| mm., width = nearly 1 mm. 



Locality and Horizon. — The collection of Dr. John Young contains 

 four specimens from the Upper Limestone Series {d^) of Gillfoot, 

 Carluke. That figured (PI. lY, fig. 4) has fifteen whorls in a length 

 of 8| mm., its width =1^ mm. In the British Museum (Nat. 

 Hist.) there is a single example of this species (G. 80), of which 

 the locahty is not given, but both the fossil and matrix bear a great 

 likeness to those from Gillfoot. This species also occurs in the 

 Lower Limestone Series {d^) at Craigenglen, Law, and Capelrig. 

 Several from the first-named locality are remarkable for showing 



