66 THE LINGULID& OF THE QUEENSLAND COAST. 
distinct and readily separable. Three young animais all with 
rather thin, horny, semitransparent valves through which 
the viscera, pallial pigmentation and pallial sinuses could 
be seen, were found to measure 26 mm. by 12.5 mm. (ratio 
2.08) ; peduncle 35 mm. ; 29.5 by 14.5 (ratio 2.03) ; 32 by 
14.5 (ratio (2.20) ; peduncle 32 mm., this specimen showing 
the presence of dark green pigment at the free extremities 
while the rest of the valves was yellowish brown, the shell 
being more calcified than those of the other two just referred 
to. Eight others, all adults with strongly calcified valves, 
were measured :—38 by 16. 5 (ratio 2.30) ; 39 by 17.5 (2.23) ; 
39 by 18 (2.17) ; 40.5 by 18.5 (2.19) ; 40.5 by 19 (2.13) ; 
41.2 by 19.5 (2.22) ; 42 by 17.7 (2.37) ; 42 by 19.2 (2.3). 
The contracted peduncle in this species is small, ranging 
up to 70 mm. but usually much shorter. All adults ex- 
amined showed the same general colouration—a very 
dark green pigmentation, especially towards the free ex- 
tremities, with green, golden and pale yellowish areas 
elsewhere. Occasionally a coppery tint was to be observed. 
The form of young shells was practically elliptical though 
somewhat broadened anteriorly, while that of adults was 
more rectangular with the sides subparallel and corners 
obtusely rounded, the anterior border possessing. a well 
marked median prominence. Hrosion of valves was com- 
monly seen. The ratio of length to breadth varies within 
considerable limits even in adults. Young forms are 
relatively broader. Since these measurements were made 
from preserved animais, they are more likely to be correct 
than those previously given, based on separated valves. 
The ranges of sizes in the two cases overlap, however, the 
ratios varying from 2.03 to 2.20 in young transparent 
forms, 2.13 to 2.37 in preserved adults ; and 2.37 to 2.52 
in the case of separated ventral valves. No doubt amongst 
the latter there has been a slight lateral contraction owing 
to drying, and this would cause the shell to appear longer 
and the ratio greater. 
Since this paper was practically completed before Mr. 
Banfield’s specimens arrived, we have not included an 
account of the anatomy of L. exusta. The pallial pigmen- 
tation is very heavy and is characteristically arranged 
