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216 CRETACEOUS GASTROPODA 
XLVIII—TURRITELLA, Lamarck, 1799. 
1. TURRITELLA (TorcULA) aspeRATA, Stoliczka, Pl. XVII, Fig. 1, and 
Pl. XIX, Fig. 7. 
Turr. testa elongate-conica ; anfractibus pluribus, complanatis, liris inequalibus 
atque striis spiralibus ornatis: lira posteriori ad marginem suturalem posita sub- 
rugosa ; lira secunda supra medium sita inequaliter duplici, acute atque numerose 
tuberculatu ; excavatione mediana anfractuum linea sub-elevata et undulata divisa ; 
liris duabus anterioribus rugosis, inequalibus, postica crassiore, antica in anfractibus 
superioribus sepe obtecta, in ultimo anfractu ad peripheriam carinam basalem for- 
mante. Superficies teste est preterea minutissime spiraliter striata, striis transver- 
talibus incrementi etiam minutis atque lente insinuatis ; basi applanata, striis non- 
nullis fortioribus atque multis tenuioribus imterpositis ornata; apertura angular 
labio moderate crasso, levigato. 
Spiral angle 19°; sutural angle 11°, 
Height of last whorl : total of shell (considered as 1:00) ... 000 eee 0°25. 
Height of penultimate whorl : height of spire (considered as 1:00) ... 0:19. 
ty fy rp es : its width (considered as 1:00) ... ee 0°48. 
This very remarkable species has an ornamentation quite different from any 
known living or fossil Zwrritella. The whorls are in their general aspect flattened, 
and the entire surface covered with a very fine spiral striation and several strong 
ridges. Beginning at the posterior or upper margin of the whorls they are placed 
in the following order: the margin of the suture is formed by a thick rough or 
obsoletely tuberculated ridge, then follows a double ridge, being unequally divided 
into a thinner posterior and stronger anterior portion; both are ornamented with 
numerous sharply pointed tubercles. Next follows a broad excavation of the 
whorls, having an undulating keel in the middle; and there are two other rough 
ridges, the one bounding the excavation being stronger, the other next to the 
lower suture thinner; the latter of these two is often partially covered by the suc- 
ceeding whorl, while on the last whorl it forms the keel of the periphery. In young 
specimens the inequality of the ridges is not so apparent, all of them being of more 
uniform thickness. The spiral striation is very distinct, and the strize themselves are 
of different strength, and slightly undulating, or occasionally interrupted in their 
course. The strize of erowth show a distinct sinuation, which is strongest on the 
tuberculated ridge, above the middle of the whorls. The aperture is angular; the 
inner lip has a moderate thickness; the margin of the outer lip has not been observed 
perfect, but judging from the curve of the strize of growth, it must have been broadly 
insinuated above the middle of the height of the whorls ; columella thin and solid. 
The only species, which appears to have a similar character of ornamentation, 
is one from the upper cretaceous deposits of Aachen, described and figured by 
J. Miiller as Turr. nodosa, Romer (Mon. Pet. Aach. Kreidef. II, 1851, p. 32, pl. 4, 
fig. 18). It differs principally from our species by a much greater height of the 
whorls, but 1 do not think that it has been correctly identified»with the species of 
Romer. I shall mention the difference again, when speaking of the Zur. nodosa. 
Locality.—Near Ninnyoor, in white calcareous sandstone ; apparently very rare. 
Formation.—Arrialoor group. 
