The History os ANIMALS. 115

The Shell-fish, on this plan of arranging them according to their Jhelh or coverings,not to the different JlruSture of the included animal, may be divided into three series } thefirst containing those formed os only one piece ; these I shall call the simple ones ; others havecalled them univalve ones, but the structure of the shell is in many\ by no means, refera-ble to a valve. The second series containing those which are formed of two parts orvalves, under the name of bivalves ; and the third, under the name of multivalves, com-prehending those whose shells are composed of several valves or parts.

S H E L L-F I S H.

Series the First.

Simple Shells.

Those which confist only of one stngle shell , and have no hinge.

PATELLA.

''HE Patella is a simple shell of a conic, or other gibbofe, figure, with a verywide opening at the bottom ; always applying itself firmly to some solidbody, which serves it in the place of another sliell: the animal inhabiting it is alimax.

The summit of the patella is in some acute, in others obtuse; in some depressed, andm some it is perforated ; and in others turned down, or otherwise crooked.

Patella vertice acuto, decem costis instruSla. 30)0 HHtltCD

The fharp-topped Lepas , with ten striae. AlMPtt.

This is a very beautiful species: the full grown ones are an inch broad at the mouth,and three quarters of an inch high ; the base is not exactly rounded, but somewhatoblong, and the top sharp or pointed : the- «>]«ur of the outside is a dusky brown,with a cast of olive ; it is elevated in ten places by so many small ridges, placed at nearlyequal distances, and is rough all over: the striae are most conspicuous toward themouth, and become fainter, as they approach the top; ‘wherethey are obliterated, andthe sharp point, and a little of the shell below it, is smooth : the inside of the shell isbeautifully variegated with brown, yellow, and whitish, disposed in the form of irre-gular circles, and in the whole shews a great general resemblance of the auricula flowers.

It adheres very firmly to the rocks in many parts of the East Indies, and elsewhere.

Patella radiata costis feptenis , feptem aculeos ad or am

efformantibus. 30)0

The radiated Patella , with seven ribs , forming seven fLtlltpCt*

prickles at the rim.

This is a very elegant and very singular species : it is but little elevated; it’s mouthis of a figure approaching to elliptic, and it’s base is about an inch long, and two thirds°f an inch broad ; it’s summit is pointed, but the height is hardly half an inch, and*he point does not rife exactly in the center of the shell: on the outer surface there areseven very elevated ribs, placed at considerable and nearly equal distances; they runstrong and distinct to the very point of the summit, and are continued to the verge,'yhere they run out each into a point beyond the rest of the verge, and form so manyprickly rays, with hollows in. form qf segments of circles between them : the colouron the outside is whitish, variegated with clouds and spots of black, especially about theribs; within it is beautifully variegated.

It is found adhering to rocks aboqt the islands of Sumatra, Borneo , and elsewhere,in the East Indies: it has been sent also from some of the American shores, and someother places.

Patella