816 NATURAL HISTOEY OF AQUATIC ANIMALS. 



," We generally found a single individual in each burrow, it being either a male or a female, 

 the latter in March or April, carrying under the tail a bundle of her eggs. Sometimes, when 

 numerous individuals are gathered on a small space, it may happen that the windings of the upper 

 parr of their burrows will accidentally meet and have in this case a communication which was not 

 contemplated. Each individual, however, remains in its own apartment; so at least we constantly 

 found to be the case. To accomplish the act of breeding, males and females must come together 

 at one particular time. In one of the burrows which we examined we found a male and a female. 

 We are inclined to believe that the male quits its retreat and goes in search of the female, as one 

 individual of the former sex was found, at one time, walking over the surface of the ground. 



"In the spring, and we are told in the fall also, the burrowing Craw-fish builds over the holes 

 of its burrow a chimney of the maximum height of one foot, but most generally lower. This 

 chimney, circularly pyramidal in shape, is constructed of lumps of mud, varying in size, irreg- 

 ularly rolled up, and piled up one upon another, and intimately connected together. Its exterior 

 has a rough and irregular appearance, whilst the interior is smooth and as uniform as the subter- 

 raneous channel, and having the same diameter as the latter. The cementing of the successive 

 balls of mud is easily accounted for when we bear in mind that the latter are brought up in a 

 very soft state, and that their drainage and subsequent solidification on their exposure to the 

 atmospheric air and rays of the sun are all that is required to unite these parts. . . . The 

 last touch consists in shutting up the aperture. This is accomplished by means of several balls 

 of mud brought up from underneath, deposited temporarily on the edge' of the chimney and 

 drawn back in close contiguity, so as to intercept all communication with the external world. 

 The number of such chimneys is sometimes very great in one particular locality, distributed 

 without any geometrical regularity, and recalling to mind the scattered habitations or village of 

 .a newly settled colony." 



226. THE SHRIMPS AND PRAWNS. 

 THE COMMON SHRIMP CRANGON VULGARIS, Fabncius. 



This species of Shrimp occurs on both sides of the Atlantic, and is eaten both in this country 

 and in Europe, it is, therefore, of considerable economic importance, though of less value than 

 the larger Shrimp (Penceus) of ttie Southern States. Crangon vulgaris, on the American coast, 

 ranges from Labrador to North Carolina, and from low-tide level to depths of about fifty 

 fathoms, "it is found in greatest abundance in shallow water, and on sandy or weedy bottoms, 

 but occurs also on muddy, shelly, and rocky bottoms, and extends at least to about fifty fathoms 

 iu depth. It varies much in coloration according to the location in which it is found. Upon the 

 exposed and light-colored sandy shores of Southern New England, specimens are invariably 

 trausluceut and very pale in color, so as to closely resemble the surface upon and beneath which 

 they live, while upon dark-colored muddy bottoms they are very much darker in color. Specimens 

 from a dark-colored muddy inlet of Vineyard Sound and others from dark muddy and sandy 

 bottoms at Halifax, Nova Scotia, are very dark indeed, the pigment spots covering nearly the 

 entire surface, and the caudal appendages becoming almost black toward the tips." 1 



" When resting quietly on the bottom, or when it buries itself partially and sometimes almost 

 entirely, except the eyes and long, slender antennae, it cannot easily be distinguished by its 

 enemies, and, therefore, gains great protection by its colors. When left by the tide it buries itself 

 to a considerable depth in moist sand. It needs all its powers of concealment, however, for it is 



'S. I. SMITH: Trans. Conn. Acad., v, p. 56, 1879. 



