268 



MARINE INVERTEBRATES 



for any other hermit common on our coast, since it has the very distinc- 

 tive feature of white longitudinal stripes on the ambulatory feet. The 

 chelipeds are about equal, rough with tubercles, and the tips have 

 smooth black edges. Body and feet are quite hairy. The color is 

 brown and white. 



GENUS Pylopagurus 



This genus is represented in Southern waters by several species. 

 One of the most characteristic of them lives in Dentalium, the 

 tooth-shell. The outer surface of the right hand is formed to 

 close the shell. All the ambulatory feet and the very small left 

 hand fold beneath, leaving only the flat surface of one hand ex- 

 posed to view. Another species lives in a shell covered with 

 polyzoans. 



FAMILY CENOBITIDJE 

 GENUS Cenobita 



C. dioffenes. This large hermit-crab, found in Florida and in more 

 southern waters, inhabits the beautiful pearly shell of Livona pica. It 

 lives on land a part of the year, but spends the breeding season in the 

 water. It can be distinguished by its land-roaming habits, its large left 

 cheliped, very stout walking-legs, and compressed eye-stalks. This spe- 

 cies climbs the hills, but is more frequently met with in low, shaded, 

 marshy places. (Plate LIX.) 



FAMILY HIPPIDJE 

 GENUS Hippa 



H. talpoida. This animal, commonly known as 

 the " sand-bug," differs greatly in appearance from 

 a crab. When the appendages are folded under the 

 carapace it somewhat resembles an egg, the body 

 being ovate, about half as broad as long, and the 

 sides forming a nearly regular curve. The carapace 

 is about one and a half inches long, convex, yellowish 

 white, and nearly smooth. The abdomen is long and 

 pressed under the body, reaching nearly to the front. 

 The eyes are minute and on the ends of long, slender 

 stalks. The antennae are plume-like and about as 

 long as the carapace. Hippa lives on sandy beaches 

 at or near low-water mark, exposed to the action of 

 the waves. It burrows with great rapidity into the 

 loose and shifting sands, using the short and stout second, third, and 

 fourth thoracic legs and the appendages of the sixth abdominal segment 



Hippa talpoida, the 

 sand-bug. 



