NOTES ON A RARE LORICATE. 
irregular towards the jugal area which is narrow, smooth and beaked. Inter 
stices between longitudinal ridges are further divided by laterals producing a 
complex gridiron pattern ; bottoms of pits thus produced are finely granular. 
In older shells erosion and the invasion of parasitic growths tend to obscure 
the finer details of sculpture. 
Posterior Valve. Mucro median, sharply angulated ; a well defined trans- 
verse ridge traverses the mucro and separates the antemucronal and post- 
mucronal areas. Postmucronal area concave, sculptured with 15 to 20 
radiating, boldly nodulose ribs. Jugal portion of antemucronal area narrow, 
smooth ; lateral portion sculptured in same manner as pleural area of median 
valves. 
Girdle. — Of medium width ; composed of oval scales which, in common 
with those of many Loricates, are larger in the area midway between valves 
and girdle margins. Scales marked with about eight deep regular grooves 
which terminate, leaving apex smooth, rounded and polished. 
* 
Interior Colour. — Tail valve green. Remainder green to greenish-yellow 
or white. 
Slitting. — Head valve, 8 to 10 slits : median valves, single slit each side : 
tail valve, 1 1 to I t slits. The usual formula for the genus is 8 — 1- — 10 or more. 
Two of the Magnetic Island shells showed ten slits in the head valve ; three 
had nine slits. Of the series of nine, four only complied with the usual formula 
and one of these four is in doubt. Appearances indicate that the normal 
eight-slit pattern is present, with the additional slits and slit-rays interposed. 
Sutural Laminae. — Rather small, semilunar, widely separated by a deep 
sinus at bottom of which may be seen a narrow coarsely serrated bridge of 
articulamentum uniting sutural laminae. 
Dimensions. — 28 x 19 mm. (max.). Others 27, 26, 25, 21, 17, and 15 mm. 
in length. 
Station. — On sides and under surface (rarely upper surface) of fairly large 
stones cemented together by edges and corners below usual tide level, but 
wholly emergent at lowest spring tides (e.g. — 4 tide). 
Range. — North Queensland Coast from Torres Strait to Capricorn Reef. 
Remarks . — They appear to be sedentary in habit and solitary 
in disposition. They were found singly, and when exposed did 
not move about. Adult shells were encrusted with calcareous 
and spongy growths and in two instances the tegmentum was 
pierced by a boring parasite without killing the host. The 
extraneous matter together with a fine coating of mud made 
them inconspicuous. Shells from the cleaner waters of Torres 
Strait or the Capricorn Reef would be less likely to be attacked 
by parasites. 
One specimen, 17 mm. in length, which showed the sculpture 
particularly well was sent to the Australian Museum for figuring 
and comparison with the type shell from Darnley Island. 
Iredale, who made the comparison, considers that they are 
undoubtedly the same species. 
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