INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 75 



by such fishes as are able to capture it. When living the colors are 

 quite elegant. Along the back there is a broad band of mottled, red 

 dish brown, which is contracted on the next to the last segment: each 

 side of this band the mottlings are fewer, and the surface somewhat 

 hairy. The last segment and the appendages of the preceding one are 

 thickly specked with reddish brown; their edges are fringed with gray 

 hairs. The CaUanassa Stimpsoni SMITH, (Plate II, fig. 8, large claw,) is 

 also a burrowing species, but its habits are at present little known, owing 

 to its rarity. It has been found in the stomach of fishes, and is proba 

 bly more common farther south. 



The Squilla empusa is a very interesting creature, whose habits are 

 still imperfectly known. It is often thrown on the beaches by the 

 waves, and probably it usually burrows in the mud below low-water 

 mark, but in certain localities it has been found burrowing at or near 

 low-water mark of spring-tides, forming large, irregular holes. The very 

 curious, free-swimming young (Plate VIII, fig. 36) were often taken in 

 the towing-nets. Large specimens are eight or ten inches long and about 

 two broad. The body is not so stout built as that of the lobster, and the 

 carapax or shell is much smaller and softer, while the abdomen is much 

 larger and longer in proportion. The legs and all the other organs are 

 quite unlike those of the lobster, and the last joint of the great claw, in 

 stead of forming a pair of pincers with the next, is armed with a row 

 of six sharp, curved spines, which shut into corresponding sockets, 

 arranged in a groove in the next joint, which also bears smaller spines. 

 By means of this singular organ they can hold their prey securely, and 

 can give a severe wound to the human hand, if handled incautiously. It 

 also uses the stout caudal appendages, which are armed with spines, very 

 effectively. The colors of this species are quite vivid, considering its 

 mud-dwelling habits. The body is usually pale green or yellowish green, 

 each segment bordered posteriorly with darker green and edged with 

 bright yellow; the tail is tinged with rose and mottled with yellow and 

 blackish ; the outer caudal lamellae have the base and spines white, the 

 last joint yellow, margined with black ; the inner ones are black, pale 

 at base; the eyes are bright emerald-green; the inner antenna? are 

 dark, with a yellow band at the base of each joint ; and the iiagellum 

 is anuulated with black and white. 



The common shrimp, Crangon vulgar is, (p. 339, Plate III, fig. 10,) is 

 frequent on muddy shores, where it has a darker color than when liv 

 ing on sandy shores. The common prawn, Palwmonetes vulgar-is, (p. 330, 

 Plate II, fig. 9,) is also common in such situations, especially where 

 there is eel-grass, among which it finds its favorite resorts, but it is 

 still more abundant in the estuaries. Another shrimp, the Virbius zos- 

 tericola SMITH, also occurs among the eel-grass, in similar places. It is 

 usually greenish in color. 



Two other species of shrimp-like Crustacea, belonging to the genus 

 Jfysis, are also found on muddy shores, especially among eel-grass. 

 7 v 



