238 



THE AMERICAN NATURALIST 



[Vol. LIV 



Selbie points out that Wollebaek (1909) showed that 

 Calocaris macandrece is normally hermaphroditic, each 

 individual having testes and ovaries. The first pair of 

 abdominal appendages has its tip expanded in all indi- 

 viduals as in male decapods. 



In some of the amphipod crustaceans, the occurrence 

 of ova in young males seems to be a normal occurrence 

 recalling the conditions in frogs. Nebeski (1880) stated 

 that the anterior end of the testis of Orchestic/, gamma- 

 rillus contained ova. DellaValle, 1893, never found 

 many eggs in Orchestia drshayesii, and none at all in 

 sexually mature males. Geoffrey Smith made some 

 further observations and attempted to explain the re- 

 sults on his anabolism-metabolism view. Ch. Boulenger 

 studied the two forms mentioned above. Out of 137 

 males of 0. gammarelhis, 135 had no ova and 2 had a few 

 ova anteriorly. Of small individuals, on the other hand, 

 nearly all contained ova in the testis (198 with and 19 

 without ova). "These results are therefore much at 

 variance with those obtained by Smith and I am at a loss 

 to explain how he arrived at his conclusions." 



Intersexes and Hybridization 

 In recent years several cases in which intersexes ap- 

 peared in considerable numbers have been shown to be 

 due to intercrossing. This raises the question whether 

 some of the aberrant individuals here described may not 

 have been due to crosses between the two species of fid- 

 dlers Uca pugnax arid Uca pugilator. It is true that the 

 latter is found most often in sandy stretches and the 

 latter on muddy flats, yet the two are not infrequently 

 found together or in nearby localities. The larger inter- 

 sexes appear to be unmistakably Uca pugnax; the smaller 

 are more difficult to identify. Miss Rathburn has exam- 

 ined both the large and the small individuals here de- 



