X LIST OF ILLUSTRATIONS. 



Page. 

 Dinichthys halmddeus. Marcellus shale (Erian), Livonia Salt Shaft, 



New York. Restoration of head-shield X g 250 



Dinognathus ferox. Cleveland Shale (Upper Devonian), Lorain County, 



Ohio. Reconstruction of the upper dental pavement 251 



Sauripterus taylori Hall. Catskill, Pennsylvania. Right pectoral limb of 



type-specimen with parts in their naturally associated position 252 



Sauripterus taylori Hall. Catskill, Pennsylvania. Restoration of the 

 right pectoral limb, seen from the inner side. The mesopterygial 

 series is represented by the humerus (H), ulna (U) and distally suc- 

 ceeding elements; the preaxial radials (R) are barely represented. 

 The scapulacoracoid, clavicle (cv), supracleithrum (5. cl.), and fin rays 

 are conjecturally restored from analogy with related genera 253 



Aspidorhynchus acutirostris Agassiz. Upper Jura (lithographic stone), 

 Solenhofen, Bavaria. Lateral aspect of cranium, XI ang, angu- 

 lare ; d. dentary ; /, frontal ; top, iuteroperculum ; /, jugal ; I, lachrymal ; 

 m, maxillary ; meth, mesethmoid ; n, rostrum ; oc. sup., supraoccipital ; 

 op, operculum ; p, parietal ; p7-d, predentary ; prf, prefrontal ; prm, 

 premaxillary ; ptf, postfrontal ; prop, preoperculum ; sang, surangulare; 

 sop, suboperculum 285 



Notogoneus osculus Cope. Green River Eocene; Twin Creek, Wyoming. 

 Dorsal (A) and lateral (B) aspects of cranium, g. (After L. Hus- 

 sakof). ANO, angular; AR, articular; D, dentary; E, ethmoid; FB, 

 frontal ; HM, hyomandibular ; lOP, interoperculum ; MtP, metaptery- 

 goid ; MX, maxilla ; OP, operculum ; PA, parietal ; PFR, prefrontal ; 

 PMX, premaxilla ; POP, preoperculum ; PSP, parasphenoid ; PTER, 

 pterotic ; Q, quadrate ; SANG, surangular ; SO, supraoccipital ; SOP, 

 suboperculum ; SPH, sphenotic ; SY, symplectic ; VO, vomer ; X, cheek- 

 plate 289 



Oarmannia spongicola 424 



1, Phyllodoce panamensis; 2. Parapodium, Leodice dubia; 3, Anterior 

 parapodium ; 4, Simple seta ; 5, Compound seta 429 



Lower cheek-teeth of Titanoides primaevus 434 



Longitudinal section of larynx of male Ruddy duck, b, rima glottidis. 



c, pulvinus laryngis. d, mouth of air-sac 481 



Figs. 1-2. — Agrion aequabile califomicum. 1. Wings of male. 2. Wings 



of female 485 



Figs. 3-10, 14-18.— Lesies stultus. 3-4. Usual coloration. 5-7. Varia- 

 tion in thoracic pattern, 8-10. Appendages of male. 11-13. — Lestes 

 uncatus, appendages of mule. 14-18. Nymph 486 



Figs. 19-32. — Zoniagrion exclamationis. 19-20. Coloration. 21-23. Ve- 

 nation. 24 and 32. Penis. 25-27. Male, appendages. 28-29. Protho- 

 rax. 30. Female, mesostigmal laminae. 31. Segments 9 and 10 of 

 female. 33. — Enallagma carunculatum, basal postcostal vein. 34-35. — 

 Acanthagrion interruptum. 34. Basal postcostal vein. 35. Penis. 

 m.— Enallagma hageni, basal postcostal vein. S7-S8.— Acanthagrion 

 gracile. 37. Basal postcostal vein. 38. Penis. 39. — Amphiagrion sau- 

 cium, penis. 40. — Enallagma poUutum, peais. 41. — Enallagma civile, 

 penis. 42. — Coenagrion puella, penis 491 



Figs. 43-52. — Zoniagrion exclamationis. 43-49. Nymph. 45. Lateral 

 carina. 46. Antenna. 47 and 49. Meutum. 48. Segment 9 of female 

 nymph. 50. Female ovipositing. 51. Eggs in leaf. 52. Egg 494 



Figs. 53-55. — Celaenura gemina. 53. Male color pattern. 54-55. Female 

 color pattern. 50-58.— Celaenura denticollis. 56. Male color pattern. 

 57-58. Female color pattern 498 



