XX 



SYNOPSIS OP 



Strophitus, Eaf., emend. Gills attached; eggs received in the whole extent of the outer gill; 

 anal opening not fringed. (Anodonta unduhta, Say.) 



Axodoxta, Brug. Gills free; eggsJhroughout the gill ; anal opening not fringed. (Anodonta 

 Benedictensis, Lea.) 



Soon after the appearance of Dr. Stimpson's publication from Prof. Agassiz's 

 MSS. I tabulated bis divisions and those of Prof. Troschel for my own use. To these 

 I occasionally added notes, and I produce the tables here for reference. 



TROSCHEL'S DIVISIONS OF THE FAMILY UXIOXIDJE.» 



Diagnosis of the Family of Uxionipje. — Shell with epidermis ; without emargination in the mantle; two muscles, the anterior of which makes 

 commonly three impressions in the shell ; one exterior ligament ; mantle without branchial and anal tubes, and without retractile muscles; two external 

 and two internal mouth lips which are large and rounded, and internally perpendicularly striate; two braochia; on each side, united to each other 

 hehind the foot for the whole length ; branchial filaments not separate. All lire in fresh water. 



Tnio. Rets. 

 tumidus. 



Margaritana. Sch. 

 margaritifera. 



Hyria. Lam. 



syriuatophora. 



Castalia. Lam. 



Dipsas. Leech. 



^Anodonta. Lam. 

 cellensis. 



Iridina. Lam. 

 cxlestis. 



Spatha. Lea, 

 rubeus. 



Mycetopus. D"Orb. 



Mouth Lips. 

 Wider than long, 

 united to mid. post. 

 margin. 



Wider than long, 

 united to % post mar- 

 gin. 



Wide as long, not 

 united. 



Little wider than long 



Animal unknown. 



Wider than long, 

 united to middle of 

 posterior margin. 



Longer than wide, 

 not united. 



Longer than wide, 

 not united. 



Longer than wide. 



Mantle, 



Margin entirely open. 



Entirely open. 



Margin inf. open. Post, closed 

 to make branchial and anal 

 aperture. 



Margin inf. open. Post, closed 

 to make branchial and anal 

 apertures. 



Margin entirely open. 



Margin united as far as the 

 foot, so that branchial and 

 anal apertnres are closed. 



Margin closed behind, so that 

 the bran, and anal apertures 

 are closed ; entirely open on 

 the under margin. 



Margin open to anal aperture, 

 which is closed. 



Bran ch iat. 

 Outer united to mantle to ex- 

 tremity. Inner not united to 

 foot. 



Outer is free posteriorly. In- 

 ner united to foot anteriorly, 

 but free the greater part. 



Outer united to the mantle to 

 extremity. Inner united to 



the foot. 



Outer united to mantle to ex- 

 tremity. Inner ? 



Outer nnited to mantle to ex- 

 tremity. Inner not nnited to 

 foot. 



Outer united to mantle to ex- 

 tremity. Inner entirely unit- 

 ed to foot. 



Outer united to mantle to ex- 

 tremity. Inner not united to 

 foot. 



Foot. 

 Tongue -shaped, thick ; 

 duced anteriorly. 



pro- 



Outer entirely united, 

 inner : 



The 



Tongue-shaped, thick ; some- 

 what produced anteriorly. 



Tongue-shaped, thick ; some- 

 what produced anteriorly. 



Tongue-shaped, thick; some- 

 what produced anteriorly. 



Tongne-shaped, thick ; some- 

 what produced anteriorly. 



Tongue-shaped, thick ; some- 

 what produced anteriorly. 



Tongne-shaped, thick; some- 

 what produced anteriorly. 



Produced and widened into a 

 knob. 



1 WUgman's Archives, 1S17, v. 13. 



* The genera Unio and Anodonta are described exactly the same ! ! 



