Vol. 54.] MISS J. DONALD ON" ACLISOIDES. 69 



affinity with Adisoides than with Murchisonia sensu stricto, but 

 the only known specimen is not sufficiently well preserved to decide 

 with certainty. 



Locality and Horizon. — Three specimens have been collected by 

 Mr. Bennie at Law, Dairy, one of which (2L Y, fig. 9) has eight 

 whorls preserved, but the apex is broken; its length = 10 mm., width 

 = 3 mm. Dr. Young (Hunterian Museum) and Mr. Neilson have 

 several specimens, and I possess one given me by Dr. Young from 

 Craigenglen. An example (PI. Y, fig. 10) in the Armstrong 

 Collection, Museum of Science & Art, Edinburgh, from the same 

 locality, is of greater size than any of the others, having six whorls 

 preserved with a length of 15 mm., width =6 mm. It is crushed and 

 partially embedded in the matrix ; the lower whorls also are so much 

 worn that the ornamenting threads are nearly obliterated. Owing 

 to these defects the whorls appear less angular, and the spiral angle 

 seems somewhat greater, than is the case in the other specimens 

 from the same locality and in those from Law. The last whorl 

 also may have originally been more convex through age ; the contour 

 of the higher whorls, however, resembles that of the other indivi- 

 duals, and the ornamentation is exactly the same. This shell is 

 remarkable for showing the lines of growth very distinctly on the 

 whorls that are worn. These are from the Lower Limestone 

 Series {d^). Dr. Young has also several small specimens from the 

 Upper Limestone Series of Glencart, Dairy (cf ). 



In Scotland the varietal form is more abundant than the type, 

 but in England the reverse is the case, for I have not met with a 

 single specimen of the variety there. 



Genus Miceentoma no v. 



Aclisina, pars L. G. De Koninck, 1881, ' Faune Calc. Carb. Belg.' Ann. Mus. Roy. 

 Hist. Nat. Belg. vol. vi, pt. iii, p. 86. 



Description. — Shell conical, composed of numerous whorls. 

 These are flat aboTe, convex below, becoming more convex with 

 increase in age, compactly coiled. Ornamentation consisting of 

 several spiral keels. Lines of growth indicating a shallow notch 

 in the outer lip, which becomes rather deeper near the aperture in 

 the adult. It is situated on the higher part of the whorl, lying 

 between two of the keels, and it never gives rise to the formation 

 of a band. Aperture imperfectly known, probably subovoid- 

 Columella slightly oblique, and thickened. Umbilicus closed. 



Resemblances. — This genus most resembles Murchisonia, espe- 

 cially the section Adisoides^ from which it is distinguished b}. 

 not having a deep narrow slit in the outer lip, but merely a notch ; 

 also the lines of growth do not sweep either backward or forward 

 so strongly. It is somewhat like the genus Fseudomurchisonia^, 

 Koken,^ but on it the lines of growth are simply curved on the 



^ ' Die Gastrop. der Trias um Hallstatt/ Jahrb. k.-k. geol. Reichsanst. 

 vol. xlvi (1896) p. 86, figs. 12 & 13. 



