Bulimulus (Drymaeus) interruptus pallidus Preston, 1909

Breure, Abraham S. H. & Ablett, Jonathan D., 2015, Annotated type catalogue of the Megaspiridae, Orthalicidae, and Simpulopsidae (Mollusca, Gastropoda, Orthalicoidea) in the Natural History Museum, London, ZooKeys 470, pp. 17-143 : 58

Bulimulus (Drymaeus) interruptus pallidus Preston, 1909

Bulimulus (Drymaeus) interruptus var. pallidus Preston 1909: 511, fig. 2.

Type locality.

"Merida, Venezuela".

Label.

"Merida, Venezuela".

Dimensions.

Not given. Figured specimen H 23.5, D 11.9, W 4.3+.

Type material.

NHMUK 1914.4.3.41, lectotype (ex Preston).

Remarks.

This varietal name has been treated as unavailable under Art. 45.6 ICZN by Breure and Ablett (2014: 96). Paul Callomon (pers. commun.) has suggested that this should be reconsidered and doubted if a lectotype of the nominal name already existed.

Our opinion is as follows:

Preston undoubtedly had a series of specimens at hand when describing Bulimulus (Drymaeus) interruptus ; both the wording "to be greatly variable" and "its principle forms" are indicative of this.

Breure (1979: 120) mentioned this taxon in his listing under Drymaeus (Mesembrinus) Albers, 1850, and stated "HT BMNH 1914.4.3.38" [referring to a single specimen, thus qualifying Art. 74.6.1.2 jo. 74.3]; Art. 74.6 ICZN rules this statement as a lectotype designation. It should be noted, however, that Breure did not list the "var. pallidus " of Preston in his paper (cf. point d below).

Köhler (1997) also concluded that this taxon was described from several specimens but said "A holotype has not been designated. Therefore, the present specimen [ZMB 59597] is a syntype. Consequently, the specimen in the BMNH referred to as holotype by Breure (1979) is a syntype". Overlooking, as explained in the previous item, the lectotype designation under Art. 74.6 (see previous point).

Reconsidering the (un)availability under Art. 45.6, it is important to note that var. pallidus was proposed before 1961 and has to be treated as subspecific (see the contributions of Steve Lingafelter and Doug Yanega on the Taxacom listing, http://to.ly/zFZO). It may be noted that the only reference to this taxon after Preston’s publication is in Baker (1926: 44), who regarded it as a synonym of Bulimus granadensis Pfeiffer, 1848 (see also Richardson 1995: 133).

While Bulimulus (Drymaeus) interruptus var. pallidus is an available name, we concur with Baker (1926) and Richardson (1995) to consider this taxon as a synonym of the nominal form.

The specimen of var. pallidus in the NHMUK is now designated lectotype (design. n.) to fixate this synonymisation. The text in Breure and Ablett (2014: 96), under 'Type material’, should be corrected as follows: "NHMUK 1914.3.38, lectotype; 1914.4.3.39-40, 42-43, four paralectotypes".

Current systematic position.

Bulimulidae , Drymaeus (Mesembrinus) interruptus (Preston, 1909).