3 1 2 S. I. ^%nU7i — Early Star/es of Hippa talpoida. 



from its gregarious habits, it is usually found in al)undauce in such 

 localities. The northern range of this, as well as of numerous other, 

 southern species is undoubtedly resti'icted by the extreme cold of the 

 winters ; and exceptionally cold seasons probably destroy a large 

 part of the individuals over considerable portions of the coast. 

 Dui'ing the summer of 1870 not a specimen of the adult or half 

 grown Hippa could be found at Fire Island Beach, Long Island, 

 although the extensive sandy beaches of that region offer specially 

 favorable localities, which were thoroughly searched ; but during the 

 last of August and early September, the young just changed from the 

 zoea, and also in a little later stage, appeared abundantly upon the 

 beaches. During the following summer no fully grown specimens 

 were found on the shores of Vineyard Sound, though half grown 

 specimens (perhaps from the young of the previous season) were 

 common. During the summer of 1875, fully grown specimens of 

 both sexes were found in great abundance at a single, very restricted 

 locality near Nobska Point, on the shore of Vineyard Sound, 

 although at this time none could be foimd at the particular locality 

 where they were common in 1871. 



Upon our shores, as far as I have observed, the Hippa inhabits 

 sandy beaches which are somewhat exposed to the action of the 

 waves. It seems to prefer only a narrow zone of the shore, at or very 

 near low water mark, where it lives gregariously, burrowing in the 

 loose and changing sands. At the locality near Nobska Point above 

 referred to, it was obtained in great abundance by digging over the 

 sand just at the edge of the receding waves. Several individuals 

 were often thrown out at a single stroke of the spade, but the won- 

 derful rapidity with which these animals burrow made it extremely 

 difficult to secure more than one or two of them at a time. The 

 smooth, oval form of the animal, with the peculiar structure of the 

 short and stout second, third, and fourth pairs of thoracic legs, enables 

 them to burrow with far greater rapidity than any other crustacean 

 1 have observed. Like many other sand-dwelling crustaceans, they 

 burrow only backwards ; and the wedge-shaped posterior extremity of 

 tlie animal, formed by the abrupt bend in the abdomen, adapts them 

 admirably for movement in this direction. When thrown upon the 

 wet beach, they push themselves backward with the burrowing thoracic 

 legs and, by digging with the appendages of the sixth segment of the 

 abdomen slightly into the sui-face, direct the posterior extremity of 

 the body downward into the sand. Upon the beaches, at least where 

 there are any waves, they seem usually to be buried completely 



