The Nautilus. 



Vol. XXX. JUNE, 1916. No. 2 



BREEDING RECORD OF MISSOURI MUSSELS. 



BY W. I. UTTERBACK. 



The following record includes twenty-six of the most repre- 

 sentative species of the different subfamilies of Naiades for 

 Missouri. Actual numbers of mussels are recorded for those 

 collected in north and northw'est Missouri but no definite rec- 

 ord of numbers of sterile and gravid individuals could be kept by 

 the author in his survey of the Osage River from the latter part 

 of June to the middle of August while under the direction of 

 the U. S. Fisheries Biological Station, Fairport, Iowa.' The 

 revised nomenclature for the Naiades is followed in this report 

 since the revival of Rafinesque ' has been accepted by the leading 

 students, and since, too, it has been found that the glochidial and 

 marsupial characters are the best bases for classification ; * however, 

 for the sake of clearness, the more familiar names appear as 

 Bynon3'ms in parentheses after the revised names. 



In the following tables the kinds of glochidia are indicated thus : 



Lamp. = Lampsilis type (i. e., suboval - subelliptic, spineless 

 glochidia). 



An.=^Anodonta type (i. e. , subtriangular, spined glochidia). 



Prop. —Propter a type (i. e., axe-shaped, spined-spineless glo- 

 chidia). 



>U. S. Bu. Fish., p:con. Cir., No. 10, 1914. 



*L. S. Frierson, 1914 a. (Nautilus, xxviii, pp. 6-8 ; E. G. Vanatta, 1915 



a, (Proc. Acad. Nat. Sci. Phila., pp. 54!)-5.59). 



» Dr. A. E. Ortmann, 1911 b, (Mem. Carnegie Mue., iv, pp. 279-339 ; 1912 



b, (An. Car. Mus., viii, pp. 222-365). 



