THE AXLMAL LIFE OF THE GROUP. 447 



may i-eadily be placed in their proper Lieiu-i-a by those who do not have aeeess 

 to more minute description. To make the illustrations more nsefid to those 

 whose collections are made mainly from the beach, the majority of the speci- 

 mens shown are in the beach-worn condition in which they are liable to occnr. 

 They were selected from matei'ial collected on four holiday excursions, one to 

 Waikiki and Diamond Head, one to the dredaer-dumped material from Hono- 

 lulu harbor, one to Pearl Harbor and one to Kahana Bay. Ninety-two species 

 belonging to forty-one genera were collected in this way. Of this niimber six- 

 teen species belonging to fifteen genera are included in a list of forty-five 

 species reported by ]\Ir. D. Thaanuni as commonly found on shore and in the 

 shallow watei- about Hilo. ]\Ir. Thaanum's collection, which includes the land 

 and fresh-water shell eolleetiou made by the Kuhns brothers, is cme of the 

 largest and most systematic private collections in the islands. The nuirine 

 collection numbers upwards of two hundred and fifty species belonging to 

 ninety of the one hundred and twenty or more genera commonly included in 

 a list of Hawaiian gasteropods. 



As an example of the unusual reward to be had for more exhaustive col- 

 lecting in a given locality for a single group of shells, it is interesting to report 

 that Mr. J. M. Ostergaard has been able, in a few years, to secure from the 

 dredging from Honohilu harbor and other sources, thirty of the forty species 

 and sub-species of the beautiful Cijprita. or cowry family, so far listed in the 

 literature of the subject as occurring in the Hawaiian Islands. 



The univalve or gasteropod mollusks are by far the largest division of 

 the Mollusea. Some are free swimming animals, living far from land out in 

 the open seas, but the greater number inhabit shallow water, usually about the 

 low-tide mark; while others dwell in brackish watei', in fresh water and on 

 the land. The typical gasteropod — and it is only this division that can be 

 considered in any detail here — is normally a crawling animal bearing a coiled 

 shell. They all move slowly by the continual contraction and expansion of 

 the muscular foot. Many of the common mariiu' forms have interesting habits, 

 and may be kept alive with very little trouble in a simple salt-water aciuarium. 

 In a small acpiarium one should lie cai-i-fuj not to overstock. Two or thi'ee 

 healthy, happy specimens are less trouble ami far more interesting for the 

 purposes of observation and study. 



In general it will be found that the sjiecies that have the base of the aper- 

 ture rounded as in Littorina, Crepkhda, Xfrita and the like, are herbivorous in 

 habit, feeding on seaweed, moss and minute aquatic plants. Shells in which 

 the aperture is deeply notched or prolonged into a canal, as in Xassa, 

 Stromb}i.'<, Mifra and Ci/pnia. are usually carnivorous or flesh-eating species 

 ami are jierhajis more difficult to supply with their accustomed food on that 

 account. 



