Bulletin of Zoological Nomenclature 58(4) December 2001 309 Comment on the proposed designation of neotypes for Vespertilio pipistrellus Schreber, 1774 and V. pygmaeus Leach, 1825 (currently Pipistrellus pipistrellus and P. pygmaeus', Mammalia, Chiroptera) (Case 3073; see BZN 56: 182-186; 57: 49-50, 113-116; 58: 60-61, 230-231) Gareth Jones School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, U.K. In response to the comment by Victor Van Cakenberghe (published in BZN 58: 230-231) I make the following observations: 1 . There is still no unambiguous morphological criterion by which bats from the 45 kHz and 55 kHz phonic types can be distinguished. The phalanx ratios described by Cabrera (1904) are not statistically different. Hence the lectotype and many of the 'other specimens' of Pipistrellus p. mediterraneus referred to by Van Cakenberghe are of doubtful identity, and this can only be resolved at present by the use of molecular markers. Although I accept that the lectotype of P. p. mediterraneus is likely to be a 55 kHz bat, at present its identity has not been confirmed and the use of this name may not, in any case, provide for a stable nomenclature over time. I am also concerned about the validity of many of the other specimens identified as P. p mediterraneus in collections throughout the world. 2. The case of Scotophilus highlighted by Van Cakenberghe is a good example of the confusion caused through instability created by changes in nomenclature. Statements such as 'Thus prior to 1978 S. nigrita referred to the largest African form and subsequent references (probably) refer to the middle-sized form' show how confusion can be created, and, in that case, the confusion continues today. 3. Recent uses of the name P. pygmaeus include Wong, J.G. & Waters, D.A. (2001) Journal of Experimental Biology, 204: 575-583; Jones, G., Vaughan, N. & Parsons, S. (2000) Acta Chiropterologica, 2: 155-170; and many abstracts and popular science articles. To use the much younger P. mediterraneus now would create immense confusion.