288 



MARINE INVERTEBRATES 



ORDER STOMATOPODA 



GENUS Squilla 



S. empusa. This animal suggests somewhat the lobster, though very 

 unlike it. The carapace is much smaller and softer, and leaves the last 

 three segments of the thorax uncovered. The abdomen is larger and 



longer in proportion, while the legs 

 and organs are quite different. 

 The whole body is depressed, in- 

 stead of laterally compressed. It 

 measures from eight to ten inches 

 in length and two inchesin breadth. 

 Instead of chelae, the last joint of the 

 great claw has six sharp curved 

 spines, which fit into sockets in a 

 groove on the second joint. By 

 this singular organ they hold their 

 prey securely. The abdominal 

 feet carry the gills. The antennal 

 scales are oblong and fringed with 

 hair. The antennules terminate 

 in three flagella. The caudal ap- 

 pendages and telson are long, 

 strong, and armed with spines. 

 This animal lives in burrows in 

 the mud below low-water mark, 

 forming large, irregular holes, but 

 is frequently washed as.hore. In 

 color it is pale yellowish-green, 

 each segment being bordered with 

 darker green and edged with 

 yellow. It is found from Cape 

 Cod to Florida. 



GENUS JHastylis 



D. quadrispinosus. Among 

 the minute Crustacea which swim 

 on the surface of the water, this 

 species, with other small forms, 

 may be captured by using a muslin 

 net. It is a quarter of an inch 

 or less in length. It is easily 

 distinguished by its large carapace, 

 the posterior portion of which is 

 marked off in transverse ridges, the anterior end running into a sharp - 

 pointed rostrum. It has a long, slender abdomen, the sections of which 



ipusa, the mantis-shrimp. 



