Mem. Nat. Mus. Vict., viii, 1934. 
NOTES ON A RARE LORICATE, RHYSSOPLAX 
EXQ ELLENS I redale and Hull. 
By John S. Mackay, M.D., Hon. Conchologist ( Loricates ), 
National Museum, Melbourne. 
Plate XVI. 
Family CHITONIDAE Pilsbry 1892. 
Genus RHYSSOPLAX Thiele 1893. 
Rhyssoplax excellens Iredale and Hull. 
1877. Chiton pulcherrimus Sowerby. Brazier, Proc. Linn. Soc. N.S.W., 
ii, 1877, 75. Darnley Island, Torres Strait. Type in Macleay 
Museum, Sydney. Not C. pulcherrimus Sowerby, P.Z.S., 1841, 103, 
from Island of Bohol, Philippine Group, in Mus. Cuming. 
1926. Rhyssoplax excellens Iredale and Hull, Aust. Zool., iv, 1926, 181, 
pi. xix, f.' 22, 27, 40. Darnley Island, Torres Strait. Type in 
Macleay Museum, Sydney. 
1928. Chiton (Rhyssoplax) excellens capricornensis Ashby, Trans. Roy. 
Soc. S. Aust., vol. 53, 1928, p. 169, pi. 12, f. 1, 13. Capricorn Reef, 
Queensland. Type in coll. Ashby. 
Historical note .— Early in 1875 the Chevert Expedition under 
the direction of Sir William Macleay left for North Queensland 
and New Guinea. They called at various points of the two 
mainlands and visited numerous islands off the Queensland 
coast and in Torres Strait. After an absence of five months 
they returned with extensive zoological and botanical collections. 
Among the islands visited was Darnley Island off the coast of 
New Guinea and here was taken a solitary example of a Loricate 
believed to be Chiton pulcherrimus Sowerby, a Philippine shell. 
It was so named by J. Brazier at a meeting of the newly formed 
Linnean Society of New South Wales of w T hich Sir William 
Macleay was the first President. 
Nearly fifty years later the Darnley Island shell was sent 
to Iredale at the British Museum for comparison with the type 
of C. pulcherrimus Sowerby. It was found to differ in certain 
details and in 1926 Iredale and Hull published it in their Mono- 
graph of the Australian Loricates as Rhyssoplax excellens (supra) . 
As only one shell 22 mm. in length was available and as 
details of exact locality, station, habits, etc., were unknown, 
the description was necessarily incomplete. 
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