392 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.54. 



BIOLOGY. 



Mr. Austin H. Clark has called the attention of the author to an 

 analogy of the parasitic life of the Strepsiptera to certain of the 

 parasitic crabs. The sea urchin, Strongylocentrotus gibhosus is 

 parasitized by a soft shelled crab, Fabia chilensis, which enters the 

 host through the anal opening, while a larva, and lives in the 

 alimentary canal as a conmiensal. It causes a distortion of the shell. 



The very degenerate crabs, Saccidina carcini, etc., live in the body 

 of other crabs and shrimj^s. 



Mr. Ed. Foster has also called attention to the parasitic isopod, 

 Probopyrus bithynis Richardson of the Bopyridae, which is parasitic 

 on shrimps. The female in the final instar is merely a sac of eggs, 

 while the males in this stage are triungulinid form. 



BELATIONS TO HOST. 



1. Actual relationship to the host. 



BBCOBDS BX SPBCIBS. 

 ANDRENA NIGROAENEA Kirby. 



Smith and Hamm (1914) found at Oxford, England, that the 

 female parasites greatly outnumbered the males. Their records are 

 based upon — 



Twenty female bees 4 of which contained male puparia ; 16 of which con- 

 tained females. 



Fifteen male bees 4 of which contained male puparia ; 10 of which contained 

 females. 



The data given do not disclose the actual number of parasites con- 

 tained in the 35 bees, but it was evidently larger than the number of 

 hosts, as one specimen illustrated contained 3 females. 



POLISTES ANAHEIMENSIS Provancher. 



Prof. L. Bruner collected a male of this wasp at Auburn, Califor- 

 nia, July 23, 1915, with a female parasite behind the fifth dorsal 

 sclerite. 



POLISTES ANNULARIS Linnaeus. 



Mr. L. T. Williams collected a female wasp at Omaha, Nebraska, 

 August 20, 1913, which contained 3 females in the fourth lateral, 

 fourth ventral, and fifth dorsal, and a male exuvium in the fourth 

 ventral segments. The females were full of triungulinids. 



Messrs E. G. Anderson and H. A. Jones collected seven parasitized 

 females at Louisville, Nebraska, August 2, 1914. These seven wasps 

 contained 58 parasites, of which 52 were males, one with 11 males, 

 one with 8 males, one with 6 males, one with 5 males, one with 4 males 



