90 USEFUL PLANTS OF GUAM. 



Among the mollusks are a number of handsome olives, cones, and 

 many small cowries which evidently feed upon the coral. There arc 

 also naked mollusks that protect themselves by spurting- forth clouds 

 of purple fluid. File-fishes, tetrodons, and other fishes are always 

 seen nibbling at the coral. Sometimes a great sea porcupine makes 

 for them, and off they all swim as though afraid for their lives. 



The natives eat man} 7 kinds of marine animals, but they do not 

 depend upon the reef to the extent that the Samoans and Caroline 

 Islanders do, having become essentially an agricultural people, and 

 few of them find it to their advantage to neglect their fields for fish- 

 ing. In former times several governors found it profitable to collect 

 and dry certain kinds of holothurians, called "trepang," or "beches 

 de mer," and ship them to Manila or Canton;" but these animals are 

 no longer sought in Guam, and are seldom eaten by the natives. 



Crabs of several kinds abound, most of them of wide distribution in 

 the Pacific. Some of them(" alimasag") have shells brightly decorated 

 with orange-red spots {Zosimus aeneus (L.)), others are covered with 

 spines, and others, when they fold in their claws, look like smooth, 

 waterworn bowlders. Scrambling over rocks along the shore are 

 Grapsus grapsus tenuicmstatus (Herbst.), of a deep red color, speckled 

 and striped with yellow. Spiny lobsters or crayfish (Panulirus), with 

 long antenna? and carapax covered with spines, abound at certain 

 points along the coast; and in the fresh-water streams on the islands 

 are delicate semitransparent prawns (Bithynis), which move about the 

 pools in a stealth} 7 ghostlike manner, and are almost invisible to the 

 casual observer. Both the spin} 7 lobsters and the prawns are valued 

 as food. 



Among the land crabs is Cardisoma rotundum Q. & G., which bur- 

 rows in the ground and does great damage to gardens. This is caught 

 in traps made of bamboo by the natives. It visits the sea at regular 

 intervals to deposit its eggs, going after nightfall in straight lines 

 and climbing over all obstacles in its way. Among the hermit crabs 

 are Aniculus aniculus (Herbst.), with a red carapax ornamented with 

 deep red spots, and Dardanus pv.net til at as (Olivier), prettily marked 

 with blue ocelli with white centers. The most interesting of all the 

 land crustaceans is the well-known Birgus latro (L.), or robber crab, 

 called "ayuyu," which is kept in captivity by the natives and fattened 

 on coconuts for the table. 



insects. b 



The insects of Guam have never been systematically collected. Many 

 of those now occurring on the island have undoubtedly been introduced 



«Chamisso, Tagebuoh, p. 243. 



^1 am indebted to Dr. W. H. Ashmead, of the U. S. National Museum, for the 

 names of the insects mentioned. 



