Primary Types in the Collection of Molluscs in the KwaZulu-Natal Museum: Polyplacophora

ABSTRACT All primary types of Polyplacophora deposited in the KwaZulu-Natal Museum are presented. The reference to the original publication, including the original generic position, the type locality, the collector and the cited dimensions of the type specimen(s), is provided for each species, followed by information from the label for each type in the NMSA collection (catalogue number, type locality and collector), size of the type specimen, brief remarks and colour photographs.


INTRODUCTION
All primary types of Polyplacophora discussed and illustrated here, were photographed during the ongoing revision of the type material deposited in the KwaZulu-Natal Museum. The historical review of the collection of molluscs can be found in our previous publication on the subject (Muratov & Davis 2011), where we presented illustrated annotations on primary types of Scaphopoda and Cephalopoda.

MATERIAL AND METHODS
The collection of the primary types of Polyplacophora in the KwaZulu-Natal Museum consists of 13 holotypes from the southeast African coast from Nacala Bay (Nampula, Mozambique) to Table Bay (Western Cape, South Africa). Some of these holotypes were not illustrated or were inadequately illustrated in previous publications, and in some cases even original descriptions were based mainly on paratypes.
Comprehensive labels were not produced by authors, except for Lepidochitona dicksae Sirenko & Hayes, 1999. All standard museum labels were produced by collection managers after types were received from authors. Names of all localities given after each type were copied from the labels, not from the original descriptions. Provincial names were standardised here using their current status.
The current status of each species is based here on the most recent comprehensive publication found and the complete synonymy is not given since this is not a taxonomic revision.
All measurements were made under a stereomicroscope using an ocular micrometer scales were individually calculated for each illustrated object and, in cases with more than one object per scale, all illustrated objects with their corresponding scales were The following acronyms and abbreviations are used: NHMUK -The Natural History Museum, London, UK (formerly known as BNHM and BMNH); NMSA -The KwaZulu-Natal Museum, Pietermaritzburg, South Africa (formerly known as the Natal Museum); SAMC -South African Museum, Cape Town, South Africa.
All shell sizes are given using the following template: l×w, where l is length and w is width in dorsal view. The reference to the original publication, including the original generic position, the type locality, the collector and the cited dimensions of the type specimen(s), is provided for each species, followed by information from the label for each type in the NMSA collection (catalogue number, type locality and collector) and measured dimensions of the holotype.
One specimen of "Chiton crawfordi E.R. Sykes, 1899" in the NMSA collection was labelled "Syntype". However, after examination of the original description (Sykes 1899: 279) and the label, it became apparent that it is a paratype of that species and therefore it is not illustrated here. Paratype NHMUK: 1932.3.29.43 (Sirenko & Schwabe 2002.

Current status: Ischnochiton oniscus
Remarks: The holotype (now in NMSA) is not accompanied by the original label. Instead there are the following: label "85. Chiton oniscus. Krs. Umkomaas", written by H.C. Burnup with the red ink note "replaced with holotype from Port Alfred", written by Ashby; another label, "Chiton oniscus. Krss. H.B. Burnup. Natal.", written by H.F. Becker; and the separate red ink note "Isch n . oniscus alfredensis Ashby Holotype. Col. by Turton in place of no 85 or 758", written by Ashby. The two paratypes collected by H.C. Burnup off Umkomaas (H.C. Burnup number 85 and possibly 758) became part of the collection of H.F. Becker. After his death in 1917, the Becker collection was bequeathed to the Transvaal Museum and in 1978 was transferred to the NMSA. However, the two paratypes in question were apparently kept by Ashby and inexplicably replaced by him at the Transvaal Museum with the holotype from Port Alfred (originally from the Oxford Museum). The labels, however, did not accompany their corresponding specimens. Instead Ashby wrote (with the same red ink as for hewitti below) two short notes indicating the replacement.
The width of the holotype given in the original publication (5 mm) is incorrect. The correct number measured in the preparation of this publication is 4.55 mm, which can Sirenko and Schwabe (2002) have mentioned that they studied the holotype of "Ischnochiton oniscus alfredensis Ashby, 1931", but did not formally classify it. In the same paper they separated I. elizabethensis from I. oniscus and gave four "principal distinguishing features" to separate them ( Sirenko & Schwabe 2002: 196-197). However, the holotype of alfredensis does not have the radula and thus, "the most stable and reliable" character cannot be checked. The width of the dorsal scales in the holotype of alfredensis is 95-140 μm, thus falling in between that of oniscus (90-110 μm) and elizabethensis (150-200 μm). Sirenko and Schwabe (2002: 195-196, 197) also mentioned that "some specimens of I. elizabethensis from Port Alfred have longer shells (like I. oniscus their postmucronal area (like I. oniscus)", and "that northern specimens of I. oniscus (from Natal and Glen Eden) have clearer and coarser sculpture of the tegmentum than specimens from Port Alfred and Port Elizabeth. Perhaps this was one reason Ashby (1931a) described the new subspecies I. oniscus alfredensis". The antemucronal area of the tail valve of the holotype of alfredensis is roughly equal to the postmucronal area and the sculpture of the medium valves of alfredensis resembles the sculpture of elizabethensis more than that of oniscus. Thus it is unclear whether alfredensis should be considered a synonym (or a subspecies) of oniscus or a synonym (or a subspecies) of elizabethensis.  (Kaas et al. 2006: 103), which was purchased by the NMSA from K.J. Grosch in September 1975. The radula (Fig. 23), which was attached to the interior of valves II and III, was not mentioned the holotype given in the original description (9.5 mm) is incorrect. The correct number

Current status: Ischnochiton bergoti
Remarks: The holotype lot in the NMSA (B7413/T2848) consists of two vials: one "SAM-A6757". Thus, two medium valves of the holotype are missing. According to the original description, the entire type series consists of one holotype (8085) and two Museum (6757) and "a few more … (S.A. Mus., No. 6757), also from Table Bay, all eroded and labelled I. elizabethensis" (Ashby 1931: 34). Five (out of eight) valves of holotype (labelled by Ashby in red ink as "holotype") and two intact paratypes (with numbers 8072 and 8082 attached to each shell and labelled as paratypes with the same red ink handwriting) were transferred to the NMSA from the Albany Museum in 1980, along with three eroded shells also labelled as paratypes (NMSA B2730/T2353) without the Albany Museum number but with the same red ink handwriting (see remarks for alfredensis). indecorus Leptochiton ( Current status: Leptochiton (L.) meiringae Remarks: The length and the width of the holotype cannot be measured correctly anymore because the holotype was damaged prior to and during the original description. Nevertheless, precise measurements of the holotype in its current condition are given above.

Current status: Chaetopleura pustulata
Remarks: All valves of holotype (except for the tail valve) are broken. The width of the is 6.77 mm, which is essentially the same as measured by a micrometer (6.59 mm).

Eastern Cape
Stn. S13, 13.vii.1984. Current status: Leptochiton (L.) permodestus Remarks: The collection date for the holotype was cited incorrectly in the original description. The width of the head valve is 3.40 mm.