MULTIVALVE SHELLS. 35 



pointed, and of a whitish colour, wherein is contained a thing in form 

 like a lace of silk, finely woven as it were, together, of a whitish colour, 

 one end whereof is fastened into the inside of the shell, even as the 

 fish of Oysters and Huskies are ; the other end is made fast unto the 

 belly of a rude mass or lumpe, which in time commeth to the shape 

 and foi'm of a bird ; when it is perfectly formed the shell gapeth open, 

 and the first thing that appeareth is the foresaid lace or string ; next 

 comes the legs of the bird hanging out, and as it groweth greater it 

 openeth the shell by degrees, till at length it is all come forth, and 

 hangeth only by the bill ; in short space often it cometh to fidl matu- 

 ritie, and faUeth into the sea, where it gathereth feathers, and groweth 

 to a fowl bigger than a Millard, and lesser than a Goose, having black 

 legs, bill or beake, and feathers black and white, spotted in such a 

 manner as is our Magpie, called in some places a Pie-annet, which the 

 people of Lancashire call by no other name than a Tree Goose ; which 

 place af resaid, and those parts adjoining, do so much abound there- 

 with, that one of the best is bought for three pence. For the truth 

 hereof, if any doubt, let them repaire unto me, and I shall satisfy them 

 by the testimonie of good witnesses." — Gerard's Herbal, p. 1558. 



The shells of this genus adhere in clusters to rocks, shells, floating 

 wood, and other e.vtraneous marine substances, and being incapable 

 oi' changing place, are supposed to be true hermaphrodites. 



Genus 3.— PHOL.\S. 



Animal an Ascidia; shell bivalve, divaricate, with several 

 lesser, differently shaped, accessary pieces, at the hinge; 

 hinge recurved, united by a cartilage; in the inside, beneath 

 the hinge, is an incurved projecting tooth. 



P/tolus crispata — The Curled Pholas. Plate V. fig. 

 3. Shell oval, gibbous, pale ochreous-yellow; part next 

 the hinge obtuse, gaping at both ends; a longitudinal furrow 

 near the centre of each valve; one half covered with muri- 

 cated waved striye and wrinkles, the other substriated. 

 2 inches long, and 3 broad. Inhabits the British coasts. 



I'liolades are found below high water-mark, biu-rowed in hard clay, 

 limestone, and \\ood, which they perforate in their younger state, and 

 as they increase in size enlarge their habitation. 



The phosphorescent property of the Pholades is very remarkable. 

 They contain a liquor which shines with uncommon splendour in the 

 dark, and illuminates whatever it touches, or happens to fall upon.* 



" There is," says Dr. Priestley, " a remarkable shell-tish called Pholes, 

 which forms for itself holes in different kinds of stone. This fish illu- 



* See Memoirs of the French Academy, 1712. 



