L. G. Brown & B. D. Neville 
Nomenclatural notes on Amaea arabica and Cirsotremafimbriolatum 
Amaea arabica (Nyst, 1871) 
Figs 3-7, 11 
Scalaria decussata Kiener, 1838: 21, pl. 7, fig. 23; 
Sowerby II, 1844: 103, pl. 35, Fig. 140; Sowerby II, 
1874: species 114, pl. 15, fig. 114a; Clessin, 1897: 39, 
pl. 12, fig. 2.; non Scalaria decussata Latnarck, 1804. 
Scalaria arabica Nyst, 1871: 105; Boury, n.d., pl. 35, 
fig. 1, 3. Nom. nov. for Scalaria decussata Sow. (non 
Lam.). Type locality: coast of Arabia. 
Cirsotrema Kieneri Tapparone-Canefri, 1876: 155; 
Kaicher, 1983: 3584. Nom. nov. for Scalaria 
decussata Kiener (non. Lam.). Type locality: none 
given. 
Amaea Sowerbyi Dunker, 1882: 69; nom. nov. for 
Scalaria decussata Sow. (non Lam.) 
Scalaria kieneri : Tryon, 1887: 81, pl. 17, fig. 21, 22, 
26. 
Amaea decussata : Cleevely, 1980: 240, fig. 2, 7. 
Amaea {Amaea) decussata'. Weil, et. al., 1999: 82, fig. 
234. 
Material Examined. Urangan, south Queensland, 
Australia, 2 dd. Palandra Beach, Townsville, 
Queensland, Australia, ldd. Swan Reefs, Queensland, 
Australia, trawled, 1 dd. 
Distribution. Red Sea, south to Mauritius, east to 
Queensland, Australia. Intertidal to 15 m. 
Remarks. In their respective monographs of the 
genus Scalaria, Kiener (1838) and Sowerby II (1844) 
each illustrated species labeled Scalaria decussata 
Lamarck. Nyst, in his Tableau Synoptique et 
Synonymique (the “Tableau") presented at the 
December 3, 1871, meeting of the Société 
Malacologique de Belgique, erected the replacement 
name Scalaria arabica for the species illustrated by 
Sowerby. Apparently, Nyst concluded that the species 
illustrated by Sowerby was not the same as Lamarck’s 
fossil species. Tapparone-Canefri (1876) erected the 
replacement name Cirsotrema kieneri for the species 
illustrated by Kiener because it was his opinion that 
Kiener’s species was distinguishable from both S. 
decussata Lamarck, 1804, and S. decussata sensu 
Sowerby II, 1844. Dunker ( 1882) also recognized that 
Sowerby’s species differed from Lamarck’s and 
erected the replacement name Amaea Sowerbyi, which 
is a junior objective synonym of Scalaria arabica 
Nyst, 1871. While Tryon (1887: 81) agreed that the 
species illustrated by Kiener was distinct from 
Lamarck’s fossil species, he went on to say that in his 
opinion, Kiener and Sowerby illustrated the same 
Recent species. Tryon, who apparently overlooked 
the replacement name erected by Nyst, used the name 
Scalaria kieneri for this species. Cleevely (1980: 240) 
commented that the species labeled Amaea decussata 
in his paper is virtually indistinguishable from 
‘ Cirsotrema ’ kieneri, documenting that there were not 
only questions regarding a possible synonymy at the 
species level, but also questions regarding the correct 
generic assignment of this species. 
Because Nyst erected the replacement name S. 
arabica based on the specimen figured by Sowerby 
under the name S. decussata, Sowerby’s figured 
specimen is the holotype of S. arabica (ICZN, 1999: 
Art. 72.7). Kathie Way at NHMUK has informed us 
that the specimen from Arabia figured by Sowerby 
under the name Scalaria decussata is supposed to be 
in the collection at her institution. She was, however, 
unable to locate it. We hâve there fore reproduced an 
enlarged illustration of Sowerby’s figure (Fig. 7). 
Similarly, because Tapparone-Canefri erected the 
replacement name C. kieneri for the specimen figured 
by Kiener under the name S. decussata, Kiener’s 
specimen is the holotype of C. kieneri. We hâve 
reproduced Kiener’s figures (Fig. 5-6). Kiener noted 
that the figured specimen is in “the Muséum 
collection.” Kiener’s material, which presumably 
included this specimen, was acquired by Delessert and 
is now in the collection at the MHNG (Y. Finet pers. 
comm.). Yves Finet provided photographs of the sole 
specimen of Scalaria decussata in the Delessert 
collection (Fig. 3-4). Because it matches well, and is 
consistent in size with, the specimen figured by 
Kiener, we consider this specimen to be the probable 
holotype of Scalaria decussata Kiener, 1838, and, by 
extension, Cirsotrema kieneri. 
Comparison of these figures confions that the 
species figured by Kiener is conspecific with the 
species figured by Sowerby. Both specimens hâve the 
same angular teleoconch whorls with cancellate 
sculpture and the basal ridge and the sculpture on the 
base of the shell appears to be the same. Because of 
the combination of the cancellate sculpture on the 
convex teleoconch whorls, the occasional varices, and 
the strong basal ridge, we consider this taxon to be 
referable to the genus Amaea. 
Figures 1-12 
1-2. Scalaria decussata Lamarck, 1804, MHNG, syntypes, photo of Fig 74 & 75 in Catalogue illustré de la 
Collection Lamarck. Mollusques Trachélipodes Fossiles, with permission. 3-4,11. Scalaria decussata Lamarck, 
sensu Kiener, 1838, length 40 mm, no locality data, MNHG 67919, probable holotype of Cirsotrema kieneri 
lapparone-Canefri, 1876. 5-6. Scalaria decussata Lamarck, sensu Kiener, 1838 (Kiener’s figure). 7. Scalaria 
decussata Lamarck, sensu Sowerby II, 1844 (Sowerby’s figure), holotype of Scalaria arabica Nyst, 1871. 
8-9. Scalaria fimbriolata Melvill, 1897, length 19 mm, width 5 mm, Karachi, NHMUK 1897.7.30.90. 
(holotype). 10, 12. Cirsotrema fimbriolatum (Melvill, 1897), length 59.6 mm, width 14.5 mm, Broome, Western 
Australia, 15 m, B. Neville coll. no. 1256. 
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