MtrSSEL FAUNA OP MAtTMEE ETVEft. 55 



ing these with a spasmodic motion, while the animal lies on its back. 

 The spawning season does not appear to be strictly confined to any 

 particular season of the year, but spaAvning individuals can occasion- 

 ally be found throughout the summer. One was observed in the St. 

 Joseph River at Fort Wayne on July 20. 



The principal parasites of L. ventrieosus are Atax,, usually few in 

 number, tlie distomid of Kelly which is frequently present but never 

 numerous, and the marginal-cyst distomid, which is occasionally 

 present in great numbers in the margins of the mantle and through- 

 out the body. 



33. Micromya fabalis (Lea). This is the smallest and one of the 

 most attractive of fresh-water mussels. It is rather rare in collec- 

 tions, on account of its small size being easily overlooked. It was 

 exceedingly abundant in the Feeder Canal; in 1908 we obtained a 

 half dozen examples, and in 1909, by going over the ground thor- 

 oughly in search of this particular species, several hundred were 

 secured. 



34. Truncilla sulcata (Lea). Scattered valves of this species were 

 seen along the shore of the St. Marys and Maumee, and now and 

 then whole shells. Shells and valves were found on the shore of 

 the St. Marys above Blutfton Street Bridge, along the St. Joseph 

 near its mouth, and in the Auglaize River. Only 1 living example 

 was found, and this was in the Auglaize. In all only 15 shells were 

 obtained. 



Truncilla triquetra was not found in the Maumee Basin, but we 

 picked up several vales on the shore of Put-in Bay Island. 



GENERAL DISTRIBUTION OF SHELLS IN MAUMEE RIVER. 



In general, as to distribution of mussels in the Maumee River, cer- 

 tain species were found to diminish in number or size, or both, in a 

 downstream course. 



Quadrula tiiberculata diminishes in both number and size until in 

 the lower part of the river only a few dead and rather small shells 

 were obtained. Dwarfed specimens were also found at Put-in Bay. 



Q. coccinea gradually diminishes and finally disappears at Grand 

 Rapids, Ohio; it was found at Put-in Bay. 



Q. i-uhiginosa greatly diminishes in numbers, but a few remain 

 until the very last. 



Q. cyUndrica,s\)iirmg\j present around Fort Wayne, was not found 

 far below Antwerp, Ohio ; no living specimens were obtained in the 

 Maumee. 



Pleurohema clava diminishes in numbers and disappears at De- 

 fiance, Ohio. 



Symphynota complanata was common and large in the feeder 

 canal and is occasional in the St. Joseph at Fort Wayne. One speci- 



