132 ruoCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



ON THE SOUTH AFRICAN POLYPLACOPHORA. 



By E. R. Stiles, F.Z.S., etc. 



Read March 9ih, 1894. 



The following paper is an attempt to bring together the more 

 important facts known concerning the Chitons of South Africa, in 

 order that some assistance may be rendered to the next compiler of 

 this fauna. I regard the known fauna as consisting of sixteen 

 species, and the number of those expunged and placed as synonyms 

 as amounting to twelve. In deaHug with Mr. Sowerby's list' I 

 expunge four, place one as a synonym, and add three. I am pleased 

 to say that I have not felt compelled to describe any new species. 



The most striking fact is the range of Ischnochiton lentiginosus, 

 which is found in South Africa and New South Wales, and on which 

 remarks will be found later. The other species found out of South 

 Africa are Ischnochiton oniscus, Acanthochites Garnoti, Acanthopleura 

 afra, and A. Quatrefagesi. 



Callochiton castaneus, Wood, 1815. General Conchology, p. 13. 

 Occurs near the Cape of Good Hope. The valve slits are as 

 follows: anterior 20, median 5, posterior 18. There is in the 

 British Museum (Natural History) a specimen under the name of 

 C. fuJgetnm, Eeeve (1847), of unknown locality, which is of a 

 marked South African form. The difference seems to be that in 

 C. fidgetrum the faint granular sculpture is slightly stronger than 

 in C. castaneus, while the line dividing the median and lateral areas 

 is not so marked: further specimens will probably show them to be 

 identical. 



Chcetopleura Watsoni, Sowerby, 1840. Charlesworth's Mag. Nat. 

 Hist. vol. iv. p. 288, Cape of Good Hope. Valve slits : anterior 7, 

 median 1, posterior 11. The species was originally described by Qaoy 

 and Gaimard as Chiton castaneus. The name was changed by Sowerby 

 on the ground that there was already a Chiton castaneus, Wood ; and 

 though these species, as now understood, belong to different genera, I 

 think less inconvenience will arise by leaving it as Chcetopleura 

 Watsoni than by reverting to the old name. 



Chcetopleura pustulata, Krauss, 1848. Die Sudafrik. Moll. p. 42. 

 Natal Coast (Wahlberg). I place this here with a little doubt, as I am 

 only acquainted with it from Krauss' work. Valve-slits : anterior 9, 

 median 1, posterior 8. The sculpture is beaded on the anterior 

 and posterior valves, and partly beaded, partly latticed, on the median, 

 while the girdle has a few hairs scattered along it. 



1 Marine Moll, of S. Africa, 1892, pp. 50, 51. 



