250 THE SPEAR-HEADED 



extremities. The segments are bordered by oval, 

 puckered leaflets, the colour of which, being almost 

 black, with an edging of light yellow green, gives the 

 animal a most beautiful appearance, somewhat re- 

 sembling that of a number of black velvet palls with 

 their light fringes. The central part of the back is of a 

 steel-blue, changing under the play of light to purple, 

 with a highly metallic reflection. The under surface 

 is of an opalescent grey.* 



The beauty in a great measure disappears on im- 

 mersion in a preservative fluid. On the first touch of 

 the solution I employ (Acetate of Alumina), a fluid 

 was poured out copiously from all parts of the animal, 

 which difi'used itself, first as a lively green tint, then 

 becoming yellow, which in about an hour became a 

 warm orange-brown, quite transparent and without 

 precipitation. 



The various kinds of spears which are grouped into 

 pencils, and placed along the sides of most of the ani- 

 mals of this Class, are among the most exquisite pro- 

 ductions with which the naturalist is conversant, and 

 show forth in a more than ordinary degree the delicate 

 and inimitable skill of the Divine handiwork. In this 

 animal they are less complicate than in some of which 

 I have had occasion to speak ; still, under a high 

 microscopic power they are well worthy of admiration. 

 In order to understand their arrangement, let me say, 

 that each segment of the body is produced on each 

 side into a little conical wart-like foot, on the upper 



• The species will probably be more completely described in the ex- 

 pected and much-desired Monograph of the British Annelida, by Dr. 

 Williams. 



