72 
XAL’TILOIDEA. 
lateral faces equal to the external one in width, converging to a 
strong keel along the middle of the inner face, the outer half of the 
lateral faces flattened, the inner half of each abruptly rounded 
nearly to a quarter of a circle ; surface under the lens marked with 
minute, subequal, slightly flexuous, longitudinal stria3 (about thirty 
in the space of two lines); a few stronger longitudinal ridges on the 
lateral keels of the external face ; lines of growth indistinct, broadly 
arched backwards on the external face, and converging at a very 
acute angle, directed backwards on the internal keel. A specimen 
of the last chamber, imperfect at each end, two inches long, has the 
lateral faces one inch four lines wide at the large end, and one inch 
wide at the smaller, the exterior face being one inch three lines 
wide at the large end ; septa moderately convex ; siphon a little 
excentric towards the external side ’* (d/‘ Coy). 
Remarhs. None of the examples of this species in the British 
Museum have the coiled, apical part of the shell preserved. A frag- 
ment showing part of the body-chamber exhibits closer septa than 
the other specimens ; a portion of the test shows distant longitudinal 
ridges, which are also faintly marked upon the cast. This may be 
a variety of T. paradox icum, or even a new species, but it is not 
perfect enough to warrant the application of a new name to it. 
De Koninck ^ figures a fragment of the present species and adds 
a dotted outline to it, supposing it to have been a shell consisting 
of about two widely separated whorls. Having, however, examined 
the original specimen in the Eoyal Museum of Natural History at 
Brussels, I can confidently affirm that there is not the least warrant 
for the attempted restoration in de Koninck’s figure. The specimen 
in the Brussels Museum agrees perfectly with Sowerby’s types in 
the British Museum, which are only very slightly curved, the apical 
extremity being, however, imperfect, so that the coiling of this part, 
as described by M‘Coy, is not exhibited. 
Horizon, Carboniferous Limestone. 
Locality. Kildare, Cork. 
Represented in the Collection by four specimens, including the 
type figured by Sowerby in the ‘ Mineral Conchology ’ (loc. cif.). 
Gyroceras (Trigonoceras) aigoceras, Miinster, sp. 
1838. Cyrtocern aiyoJceros, Miinster, Beitriige znr Petrefiictenkunde, 
(1st ed.) Heft i. p. 33 (2nd ed,), Heft i. 1843, p. 5G, Taf. i. fi. 7 a, 
7 6, Taf. ii. f. 1. 
‘ Faune du Calcaire Carbonifere de la Belgique (Annales du Miis. Roy. 
d’Hist. Nat. de Belgique, tom. v.), pt. ii. 1880, p. 7, pi. xxxii. fig. 3. 
