lO. NAIADES OF MISSOURI 



Genus XX. Cyprogenia (Agassiz) 



48. C. Aberli (Conrad) — (3. c) 



(15). C. Aherti Lamarckiana (Lea) — (3. c) 

 b. — Marsupium with compressed and dilated ovisacs; post ventral 

 margin of mantle smooth to papillose; shell generally without disk 

 sculpture, sex dimorphism usually very distinct. 



(a) — Inner post-ventral edge of mantles without flap or papillae, 

 but slightly lamellate and crenulated; glochidia elliptic and celti- 

 form, when normal in shape either extremely large or small. 



Genus XXI. Obovaria (Raf.) 

 Sub-Genus (I) — Pseudoon (Simpson) 



49. 0. {Pseudoon) ellipsis (Lea) — (i. b) 

 Genus XXII. Nephronaias (Cross and Fisher) 



50. N. ligamentina (Lamarck) — (i. b) 



(16). A'^. ligamentina gibba (Simpson) — (i. c) 



51. N. ellipsiformis (Conrad) — (i. c) 



(17). N. ellipsiformis vennsla (Lea)— (i. c) 



52. N. Pleasii (Marsh) — (3. c) 



53. N. ozarkensis (Call) — (3. c) 



Genus XXIII. Amygdalonaias (Cross and Fisher) 



54. A. donaciformis (Lea) — (i. a) 



55. A. truncata (Raf.) — (i. c) 

 Genus XXIV. Plagiola (Raf.) 



56. P. securis (Lea) — (1. b) 

 Genus XXV. Lasmonos (Raf.) 



57. L.fragilis (Raf.) — (i. a) 



58. L. Simpsoni (Ferriss) — (3. c) 



59. L. leptodon (Raf.) 

 Genus XXVI. Proptera (Raf.) 



60. P. alala (Say) — (i. a) 



61. P. purpurata (Lamarack) — (3. c) 



62. P. laevissima (Lea) — (i. a) 



63. P. capax (Green) — -(i. b) 



(b) — Inner post-ventral edge of mantle differentiated with papillae 

 and flaps; glochidia normal in shape, medium in size. 



Genus XXVII. Carunculina (Simpson) 



64. C. parva (Sarnes) — (i.b) 



65. C. texensis (Lea) — (i. a) 



66. C. glans (Lea) — (i. a) 

 Genus XXVIII. Eurynia (Raf.) 



Sub-Genus (II). Micromya (Agassiz) 



67. E. {Micromya) lienosa (Conrad) — (3. c) 



68. E. {Micromya) iris (Lea)— (3. c) 



69. E. {Micromya) hrevicula (Call) — {t,. c) 



(18). E. {Micromya) brevicula Britlsi (Simpson) — (i. c) 

 Sub-Genus (III).) Eurynia {sens, strict.) 



70. E. {Eurynia) suhrostrata (Say) — (i. a) 

 7 J. E. {Eurynia) recta (Lamarck) — (i, c) 



