4 THE NAUTILUS. 



R. N., in the British Medical Journal, Jan. 30, 1915, dealing 

 with Schistosoma, and having as an appendix a note by Mr. 

 G. C. Robson describing the mollusk which serves as host for 

 its cercarise. This mollusk is called Katayavia nosophora n. g. 

 et sp. It is undoubtedly identical with the form sent me by 

 Professor Goto, and described above. As I have already had 

 the figures for my article engraved, I allow it to stand as writ- 

 ten, merely substituting Mr. Robson's specific name for my 

 own. It may be useful to point out that the mollusk in 

 question belongs to the long-known genus Blanfordia, and that 

 the new genus Katayama is therefore superfluous. Mr. Rob- 

 son was naturally misled by the wrong position assigned Blan- 

 fordia by the older authorities. 



SOME EXCEPTIONAL CASES OF BREEDING AMONG THE TJNIONIDJE.' 



BY ARTHUR D. HOWARD. 



In collecting material for the study of a somewhat peculiar 

 case of breeding among the Unionidse, I have incidentally come 

 upon some other instances, which I believe have not been re- 

 ported. In 1912 I undertook to work out for the United States 

 Bureau of Fisheries, methods of propagation of the Washboard 

 mussel, Quadrida heros Say, with other species of Quadrula. 

 This species was somewhat uncommon in the vicinity of the 

 laboratory where I was stationed, so that there was a question 

 as to a supply of material. One day I noticed a boatload of 

 shells containing an unusual number of Q. heros with many 

 young shells. Enquiring of the owner the source of these, I 

 learned they had come from Moline, 111., some 25 miles above. 

 I subsequently visited the place, finding it accessible and the 

 species suflSciently abundant to furnish considerable data on 

 breeding as well as material for experiments in propagation. 



While collecting the Washboard mussel at this point I ob- 

 tained evidence of peculiarities in the breeding of three other 

 Unionidae which, although they may not be of immediate im- 



* Contribution from United States Biological Station, Fairport, Iowa. Pub- 

 lished by permission of Commissioner of Fisheries. 



