OVR CARCmOLOGICAL FRIENDS. 97 



these (Idoiea cceca) is the little creature whose ser- 

 pentine tracks over the sand have so frequently 

 called forth the query, What animal made them ? 

 The species is found all the way from Massachusetts 

 to Florida. A second form {Stenosoma irroraia, PL 

 7, Fig. 4), of a deep-purple or sea-green color, will 

 probably be recognized by many as the active spirit 

 of the quieter waters, whose gyrations strongly sug- 

 gest a scheme of self-imposed perpetual motion. A 

 third species {Limnoria terebrans, PI. 7, Fig. 2) can 

 generally be found only beneath the water-surface, 

 where it attacks almost any timber — piles, piers of 

 bridges, wharves, etc. — that may be brought within 

 its reach. It is asserted that piles lose as much as 

 an inch in diameter annually through the ravages 

 of this pest. Coating with verdigris or creosote, 

 or sheathing with metallic copper, has proved effi- 

 cacious as a preventive of destruction. 



In all these forms the body is largely symmetrical 

 in outline, and the numerous pairs of legs are of 

 nearly equal size and equally disposed along the 

 sides of the body ; hence the term Isopoda, equal- 

 footed, that has been applied to the group in general. 



SQUILL. 



Our description of the Crustacea of the coast 

 would not be complete without reference being 

 made to a somewhat rare species, the squill, which 

 is figured on the following page. The animal can 

 be immediately recognized by its greatly elongated 

 and flattened body, measuring from four to six, 

 or exceptionally ten, inches in length, the great 

 Kg 9 



