NOTES ON A RARE LORICATE. 
In 1928 Edwin Ashby published a short account of a shell 
received from the Capricorn Reef, where it had been collected 
by W. J. Kimber. Ashby recognised the close relationship of 
this specimen to the rare R. excellens, but, believing the Capricorn 
shell to differ subspecifically, he published it as Chiton ( Rhysso - 
plax) excellens capricornensis (supra). 
' ' )V 
Until recently these two specimens from widely divergent 
localities nearly 800 miles apart were the only ones known. 
In August 1931 the present writer took advantage of the 
exceptionally low new moon tide to examine the littoral on 
the south side of Magnetic Island, North Queensland. Close 
to the jetty at Nellie Bay are some piles of granite fragments, 
evidently debris from the road which has here been blasted 
from the solid rock. The granite is fine-grained and tends to 
fracture with a smooth surface. The fragments of rock lay in 
piles extending below the lowest tide level and had become 
somewhat cemented together at the edges by coralline debris. 
Over an area of about nine feet square a colony of nine individuals 
of Rhyssoplax excellens was found. 
This fine series permits some expansion of the original 
description. 
General Appearance. — Elongate ovals of medium size, strongly elevated, 
carinate, of complex sculpture. 
Colour. — Variable. 
1. Type. Darnley Island. “Creamy brown, the girdle with darker 
banding.” 
2. Ashby’s specimen from Capricorn Reef. “Creamy white, with bright 
red blotches on six of the valves.” - : .x :>« 
3. Magnetic Island specimens, a. Creamy brown, jugal areas touched 
with darker brown ; girdle banded cream and brown, b. Cream, umbones of 
valves 2, 4, 5 and 6 and lateral portions of pleural areas of valves 2 to 8 maroon ; 
girdle banded cream and reddish brown, c. Yellow, umbones and lateral 
areas tinted green ; girdle banded yellow and green. 
Anterior Valve , — Strongly erect, conspicuous from other valves. Sculpture 
consists of 20 to 25 radiating strongly nodulose ridges in adult shells ; juveniles 
show a smaller number of ridges, but in between may be seen all stages from a 
single nodule up to the fully developed ridge. Apical tip smooth and polished. 
Posterior margins show from 1 1 to 20 serrations on each side ; this feature, 
which is beautifully shown in young specimens, may, from erosion, be less 
apparent in adults. 
Median Valves. — Second valve larger than the others. Lateral areas 
strongly elevated with usually three (rarely four) bold, nodulose ribs ; when 
lour ribs occur, it is usually on the second valve. Juveniles may show two 
strong ribs and a weak one between. Posterior margins strongly toothed as 
in the anterior valve. Pleural areas crossed by 12 to 16 strong longitudinal 
ridges with deep interstices at lateral margins ; they become shallow and 
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