Involute.] 



MOLLUSCA. 



39 



This species is subject to the following very distinct varieties : 



1. With four plaits, the middle ones less than the others. 



2. With five plaits, the three middle ones less than the 

 others. 



3. With five plaits, the three lower ones less than the 

 others. 



Found first in Britain by Mr. Rolph, in Charlton Wood, 

 Kent ; and Mr. Gray has met with it at Hastings, Sussex. Its 

 habitat is in damp woody situations, among moss, and on the 

 trunks of trees. 



5. Clausilia dubia, pi. XVIII, f. 32. 



Clausilia dubia, Drapernaud, Hist, des Moll., p. 142, pi. 4, f. 

 10 ; Alder, Mag. Zool. and Bot., II, p. 1 1 1 ; Clausilia rugosa, 

 var. t Alder, 1. c, p. 32 ; Clausilia similis, Gilbertson, MSS. 



Shell dark umber-brown, ventricose; body long; spire small, 

 consisting of from nine to eleven rather inflated volutions ; 

 covered with pretty strong, elevated, somewhat granular stria?, 

 iu consequence of a few spiral ridges on the lower volutions ; 

 aperture oblong-ovate, contracted above, and a little rounded 

 below; lips white, rather narrow; columella with two plaits, the 

 superior one placed near the upper portion of the aperture and 

 pointing downwards, the lower one near the under side, inter- 

 nally bifurcate, and pointing upwards. Size, about five-eighths 

 of an inch long, and one-eighth in diameter. 



It is known from Clausilia rvgosa by being longer, and 

 more ventricose. 



Found in the North of England, under moss in rocky situa- 

 tions. 



Genus 50 — Pupa Lamarck. 



Shell oblong, cylindrical, thick ; spire with numerous volu- 

 tions, terminating in an obtuse apex ; aperture elliptical for the 

 most part, sometimes a little square at the upper extremity, 

 and rounded anteriorly; peretreme and inner lip continuous, 

 slightly thickened, and reflected ; upper part of the aperture 

 frequently provided with a single tooth within : many of the 

 species furnished with longitudinal ribs. 



The young shells of the genus Pupa are trochiform, with a 

 simple cavity at the base. Mr. Alder first pointed out a 

 remarkable structure in the interior of Piqm umbilicata and 

 P. Anglica. This consists of a raised thread-like laminar 

 process winding spirally round the columella, and a similar 

 lamina running spirally on the upper side of the volutions, with 

 a series of small, flat, nearly transverse, testaceous plaits, situate 

 at intervals, in the interior of the volutions. These are some- 

 what analagous to the septa in the genus Segmentina. These 

 plaits are not, however, continued through the lower volutions. 

 Their use has not yet been ascertained. 



1. Pupa muscorum, pi. XIV, f. 7. 



Pupa muscorum, Drapernaud, Hist, des Moll., p. 59, var. a; 

 Pfeiffer, I, p. 57, pi. 3, f. 17, 18; Pupa delucida, Rossmassler, 

 VI, p. 15, pi. 23, f. 326; Bulimus muscorum, Bruguiere, Ency. 

 Meth., p. 334, No. 63 ; Helix muscorum, Miiller, Verm. Hist., 

 II, p. 105, No. 304; Turbo muscorum, Linnaeus, Syst. Nat., p. 

 1240, No. 651 ; Chemnitz, Conch., IX, pi. 3, f. 3; Maton and 

 Racket, Linn. Tr., VIII, p. 182; Turton, Brit. Fau., p. 184; 

 Donovan, Brit. Sh., Ill, pi. 80. 



Shell subcylindrical, smooth, glossy ; body somewhat shorter 

 than the spire, which consists of four rather broad volutions, 

 gradually tapering to a somewhat obtuse apex ; aperture sub- 

 ovate, destitute of teeth ; outer lip white, rather narrow above, 

 but widening a little below; pillar lip narrow ; whole surface of 

 a fulvous brown-colour. 



Found at the Rabbit Burrow, Portmarnock, Ireland ; near 

 Weymouth, Dorsetshire; at Corstorphin Hill, near Edinburgh, 

 and in the park of the Earl of Rothes, near Leslie, Fifeshire, 

 on the bark of trees and among moss. 



This seems the true P. muscorum of Linnaeus; and I cannot 

 agree with Rossmassler and other modern authors, in consider- 

 ing the P. unidentata and bideniata as varieties of this species. 



2. Pupa unidentata, pi. XIV, f. 4 First Ed., pi. 41, 



f. 4. 



Pupa unidentata, Pfeiffer, Land tin Was. Sn., I, p. 58, pi. 3, 

 f. 19, 20; Pupa muscorum, Gart, Conchy 1. der Wetterau, S. 

 20 ; Rossmassler, I, p. 83, pi. 2, f. 37 ; Turbo muscorum, V. 

 Alten, Erd-und Flussconchyl., un Augsb., S. 23. 



Shell smooth, brownish horn-coloured, subcylindrical ; con- 

 sisting of seven narrow, slightly inflated volutions, terminating 

 in an obtuse apex; aperture suborbicular, sublimate above, with 

 a single sharp, prominent tooth placed on the base of the body, 

 margins white and smooth. Length a little more than an eighth 

 of an inch ; diameter a third of its length. 



Distinguished from P. marginata by the single tooth being 

 more acute, and placed farther forward. 



Found with other species of Pupa at Portmarnock Rabbit 

 Burrow, Ireland. 



3. Pupa bidentata, pi. XIV, f. 6 First Ed., pi. 41, f. 6. 



Pupa bidentata, Pfeiffer, I, p. 59, pi. 3, f. 21, 22. 



Shell ovate, ventricose ; body and spire of nearly equal 

 length ; the latter consisting of four considerably inflated volu- 

 tions, the three superior ones rapidly diminishing, and termi- 

 nating in a rather sharp apex ; aperture subovate ; outer lip 

 slightly reflected, and white ; pillar lip narrowly reflected on 

 the columella, with a narrow subumbilicus behind it ; whole 

 surface covered with a chestnut-brown epidermis. Length not 

 two lines ; diameter equal to two-thirds its length. 



Found at Portmarnock, Ireland. 



This species is much shorter, in proportion to its breadth, 

 than the P. marginata, and is always destitute of the rib be- 

 hind its outer lip. 



Notwithstanding the opinion of Rossmassler and other 

 authors, I always have considered that the P. muscorum, 

 unidentata, and bidentata are distinct species ; for besides the 

 dentition, the following distinctions will be found in the three 

 nearly allied species of this genus. In P. muscorum the shell 

 is subcylindrical, the whole volutions a little more oblique than 

 in the other species, and gradually decreasing, with the apicial 

 one rather obtuse; and the body and first volution longer. P. 

 unidentata is nearly cylindrical, the volutions are more trans- 

 verse, the three apicial ones diminishing more abruptly, with 

 the superior one more pointed. P. bidentata is altogether a 

 shorter shell in proportion to its breadth. 



4. Pupa marginata, pi. XVIII, f. 33, 34. 



Pupa marginata, Drapernaud, Hist, des Moll., p. 61, pi. 3, 

 f. 36, 37, 38; Pfeiffer, Land un Was. Sn., I, p. 59, pi. 3, f. 23, 

 24 ; Brard, p. 93, pi. 3, f. 15, 16 ; Turton, Man., p. 98, f. 79 ; 



