OSTREADiE. 
347 
Wrongly reminded one of the arrangements of the teeth of a comh, 
"hence their name of Pecten. They were well known to naturalists 
'°Cg before the time of Linnaeus, under the name of Pilgrims shells, 
" "arne which came into use from the practice which prevailed among 
Mgrims in the middle ages — we know not why— of ornamenting 
^hits and hats with the valves of some of the species. 
The shell of the Pecten is in general nearly circular, more or less 
^° a gated, and terminated towards the summit in a straight line, 
joining a sort of triangular appendage called the car, to which the 
^ges are attached. The valves are very 
Aguiar, hut with no resemblance to each 
°tker. I n gome species, the shell of which 
!** c losely shut, the lower valve is more or 
® Ss convex than the upper one. In others, 
10 lh valves are convex. The hinge is 
"'tliont teeth, and the ligament, which is 
^tended to close the shell, is inserted into 
Angular depression or dimple. The re- 
ptile muscle is unequal, and nearly central. 
Ie valves are not nacred inside, and are 
0 r >'ie<l on their exterior surface of numerous fluted channels, which 
s Pritig fro m a lobe more or less pointed at the summit, diveiging 
'c^ards the circumference. The 
I-is?. 
13 1. Pecten pseudatnussium 
(Cbenu). 
Cd 
flie 
are sometimes smooth, as in 
. Watered Pecten (P. pseudetmus- 
Pig. 134) ( but more frequently 
G y are formed in strips or. scales, 
^ the Smooth- shelled Pecten (P . 
•Mfcer, pjg -| 35 ). Upon the whole, 
clever, the Pectens are very vari- 
e > tut always elegant in form ; the 
°ci's are frequently lively and bril- 
' a ut. I u p L XIV., some of the most 
'king forms are represented, as 
1., the Ducal Mantle ( Pecten 
^ liu »i), an inhabitant of the Indian Ocean, remarkable for its elegant 
a* 111 ! Its twelve radiating stripes, diverging towards the circumference, 
c horizontal furrows of its salient scales, and the striking distribution 
Fig. 135. Pecten gl&ber (Unnaus). 
