LIST OF TLLUSTEATIONS. XIII 



I'ago. 



Exonautes brachycephaha< 539 



Cypsilurns agoo 541 



Internal and external aspect of left quadrate of Hesperornis gracilis 546 



Superior and inferior views of right pterygoid of Hesperoriiis gracilis 546 



Supposed lachrymal of Hcsperornitt regalis 547 



Right clavicle and part of right coracoid of Hesperornis regalis, natural size . . . 549 

 Lateral, palatal, and dorsal views of the anterior portion of the cranium of a 



young cormorant, Phalacrocorax nrile 551 



Right coracoid and portion of left scapula of Baptornis adtrnufi 554 



Left humerus, radius, and ulna of Baptornis advenvs 554 



Right padella of Baptornis advenns 555 



Cephaloscyllium umbratile 603 



Chiloscyllium indiciun (305 



Squalus mitsukurii 630 



Deanica eglantina: 0, upper jaw; }>, lower jaw; c, scale 632 



Etmopterus lucifer: a, upper jaw ; b, lower jaw (534 



Centrocyllium ritteri (535 



Baja mecrdervoorti (351 



Baja tengu (354 



Dasyaiis akajei (j(30 



Mobida japonica (from a f(etus) 666 



Cottuncidus brephocephalus (390 



Embohchthys mitsukurii (393 



Zen ilea _ (394 



Hejiiochus dipJireutes (395 



Acanthocepola limbata 702 



Tracheation of the wings of two nymphs oi Gotnplius dmrljitus Banks, two 



early stages 706 



Fore and hind wings of a grown nymi)h of Gotnphus descriptus, showing 



trachea^ 707 



Venation of the imago of Gomphus d^scriptus 708 



Pterostigmas: p, of Anax Junius Drury; q, of Miathyria )narrella Selys; r, of 

 Neogomphus molesfus Selys; s, of Uropetala carovei Selys; /, of Agrion mer- 

 curiale Charpentier; u, of Anomalagrion hastatmn Say; r, of TJiore gigantea 

 Selys; «•, of Mecistogaster lucretia. Drury; x, of Calopteryx macnlata Beau- 



vois; (/, Microstigma sp. (?); z, Microstigma rotundatitm Selys, hind wing.. 709 



Tracheation of the nodal region of the nymphal wing of Av.(ix junins Drury. . 712 

 Tracheation of the nodal region of the nymphal wing of LlbeUula pidchclla 



Drury 712 



Tracheation of the nodal region of the wing: a, of IHdyrnops fraii.sirrsa Say; 



b, of Cordulegaster diastatops Selys 713 



Wings of Epigomph us paludosus Selys 715 



Wings of a fossil, undescribed, Agrionid genus, in the Museum of Compara- 

 tive Zoology 71(3 



Wings of Tetrathemiff hyalina Kirby 716 



Diagram illustrating tlie behavior of the quadrangle in the Calopterygidir 717 



Diagram setting forth the l)ehavior of the triangle in the suborder Anisoptera . 717 



Wings of Microdiplax delicatula Selys 718 



Diagram showing base of typical dragon-fly wing 719 



Diagram illustrating the procession of the triangle and the deflection of the 



anal vein and second cubito-anal cross vein in the fore wings of Libeltulidiv.. 720 

 Diagram representing the recession of the triangle in the hind wings of the 



Libellulida: 721 



