LIST OP ILLUSTRATIONS. IX 



Page. 



Figs. 111-138.— Genital stipites of 111-112, Bicyrtes fodiens; 113-114, B. 

 ventrnlis; 115-116, B. parata; 117-118, B. 4-fasciata; 119-120, B. varie- 

 gata; 121-122, B. annulata; 123, B. gracilis; 124-125, B. viduata; 126- 

 127, B. imidiatrix; 128-129, B. capnoptera; 130-131, B. mesillensis ; 132, 

 Middle femur of B. ventralis, male ; 133, B. capnoptera, male ; 134, Pos- 

 terioi- coxae of B. fodiens, female ; 135, Ultimate tergite of B. fodiens, 

 female ; 136, B. burmeistcri, female ; 137, B. annulata, female ; 138, B. 

 capnoptera, female 148 



Figs. 139-184.— Genital stipites of 139-140, BemUx arcuata; 141, B. U- 

 scripta; 142-143, B. cinerea; 144-145, B. hinei; 146-147, B. nubili- 

 pcnnis; 148-149, B. amoena; 150-151, B. satji; 152-153, B. belfragei; 

 154, B. steneMoma; 155-156, B. foxi; 157-158, B. spinolac ; 1.59-160, B. 

 spinolae, showing variation; 161-162, B. cameroni; 163-164, B. comata; 

 165, B. comata, showing variation; 166-167, B. primaaestate ; 168, B. 

 primaaestate, showing variation; 169-170, B. similans; 171-172, B. 

 pruinosa; 173-174, B. beutenmulleri ; 175-176, B. occidentaUs; 177-178, 

 B. troglodytes; 179-180, B. melanaspis; 181-182, B. texana; 183-184, 

 B. lielianthopolis 149 



Figs. 185-211. — Antenna of 185, Bcinbix arcuata, male; 186, B. cinerea, 

 male, 187 ; B. hinei, male ; 188, B. nubilipennis, male, 189, B. amoena, 

 male ; 190, B. sayi, male ; 191, B. belfragei, male ; 192, B. stenebdoma, 

 male ; 193, B. foxi, male ; 194, B. spinolae, male ; 195, B. cameroni, male ; 

 196, B. comata, male; 197, B. primaaestate, male; 198, B. similans, 

 male ; 199, B. pruinosa, male ; 200, B. beutenmulleri, male ; 201, B. occi- 

 dentaUs, male; 202, B. troglodytes, male; 203, B. melanaspis, male; 

 204, B. texana, male; 205, B. helianthopolis, male; 206, Clypeus and 

 labrura of B. arctita, lateral view ; Middle tibia and metatarsus of 207, 

 B. arcuata, male ; 208, B. U-scripta, male ; 209, Middle tibia and tarsus 

 of B. Jiinei, male ; Middle metatarsus and tibial spur of 210, B. amoena, 

 211, B. sayi 150 



Figs, 212-230. — Clypeus and labrum of 212, Bembix belfragei, lateral 

 view ; 213. Sixth tergite of B. belfragei, female ; 214. Middle tibia and 

 metatarsus of B. stenebdoma; male; 215, Ventral view, sternites 6-8 of 

 B. stenebdoma, male ; 216, Sixth tergite of B. rugosa, female ; 217, Cly- 

 peus and labrum of B. rugosa; Process on second sternite of 218, Micro- 

 benibex aurata, male ; 219, M. monodonta, male ; 220, M. hirsuta, male ; 

 Genital stipites of 221-222, M. aurata; 223-224, M, hirsuta; 225-226, 

 M. monodonta (Ohio) ; 227-228, M. monodonta (Florida) ; 229-230, M. 

 monodonta (Washington) 151 



Dorsomedian shield of Psammosteus paradoxus Agassiz, wanting super- 

 ficial ornamentation. Upper Devonian, Neuhausen, LivoniaJ 242 



Pattern of skull-top of Devonian Dipnoans. A, Diptcrits ralenciennesi. 

 B, Scaunwiiacia curta. In specimens of dipterus the numerous sen- 

 sory pits are scattei-ed over broad tracts, the general directions of 

 which are indicated by the dotted lines, except in the occipital region 

 where the dotted lines represent shallow grooves. The "parietals," 

 " frontals," etc., are probably not homogenous with those of Tetra- 

 poda. Dso, dermosupraoccipital ; Fr, frontals ; Na, nasoethmoid region ; 

 St. supratemporal (pterotic) ; Tb, tabuiare (epiotic) ; Parietal, pre- 

 parietal 247 



Dinichthys bulla Upper Devonian, Wildungen, Germany. Restoration of 

 head-shield, slightly modified after Jaekel. C, central; EO, external 

 occipital ; M, marginal ; MO, median occipital ; P, pineal ; PO, pre- 

 orbital ; PtO, postorbital ; R, rostral ; SO, suborbital 249 



