92 Bulletin American Museum of Natural History. [Vol. XXIII,. 



Fig. 26. — Phthisergate of Ph. instahilis viewed as a transparent object to show 

 the urate masses in the gaster. From a specimen mounted in balsam. 



Fig. 27. — Normal worker pupa of Ph. instabilis in profile. From an alcoholic- 

 specimen. 



Fig. 28. — Phthisergate of Ph. dentata Mayr. From an alcoholic specimen. 



Fig. 29. — Worker cocoon of Gamponotus herculeanus ligniperdus var. novceboracen- 

 sis Fitch, from northern Michigan, showing an enclosed pair of pups& 

 of Pseudochalcura gibbosa Provancher near the anterior pole, and the 

 remains of the consumed Camponotus semipupa applied to the black 

 meconial spot at the posterior pole. 



Figs. 30-35. — Six larvis of Orasema viridis in the youngest stage observed, corre- 

 sponding with the one shown in Fig. 13. 



Plate III. 



Fig. 36. — Pkeidoloxenus wheeleri Ashmead. Female, taken from a colony of Ph. 

 instabilis at Austin, Texas. 



Fig. 37. — Pheidole dentata var. commutata Mayr. Soldier. New Braunfels, Texas.. 



Fig. 38. — Ph. commutata. Worker. 



Fig. 39. — Mermithergate of Ph. commutata, drawn to the same scale as Figs. 37 and 

 38; showing Mermis parasites in the distended gaster. The head of 

 the ant bears occelli; the thorax is shaped like that of the soldier. 



Fig. 40. — Lateral view of same mermithergate. 



Fig. 41. — Xenodusa cava Leconte, taken from a colony of Formica schaufussi var. 

 incerta Emery at Colebrook, Connecticut. 



Fig. 42. — Formica schaufussi Mayr. var. incerta Emery. Normal worker. Cole- 

 brook Connecticut. 



Fig. 43. — Pseudogyne of F. incerta drawn to the same scale as Fig. 42. 



Fig. 44. — Pseudogyne from the same colony as Fig. 43, showing a somewhat differ- 

 ent conformation of the thorax. 



Plate IV. 



Fig. 45. — Pseudogyne of Myrmica rubra hrevinodis Emery var. sulcinodoides 



Emery, with vestige of left fore wing, from Isle Royale, Michigan. 

 Fig. 46. — Thorax of same in profile. 

 Fig. 47. — Thorax of normal worker of M. sulcinodoides. 

 Fig. 48. — Thorax of pseudogynic M. rubra scabrinodis Nyl. var. schencki Emery,. 



from Jeanette, Pennsylvania. This specimen has minute vestiges 



of both fore wings. 

 Fig. 49. — Lateral view of same. 

 Fig. 50. — Pseudogyne of Formica rufa obscuriventris Mayr. var. melanotica Emery, 



with well-developed mesonotum, scutellum and metanotum, from 



Rockford, Illinois. 

 Fig. 51. — Dorsal view of thorax of same. 

 Fig. 52. — Pseudogyne of F. melanotica with more convex mesonotum, from the 



same colony as the specimen shown in Figs. 50 and 51. 

 Fig. 53. — Pupa of female Orasema coloradensis Ashm.; dorsal view showing the; 



arrangement of the pustules. 



