vol.i.] Torrey. — Hydroida of the Pacific Coast. 25 



93. Hydroeladia borne directly on stolon Antenella avalonia (p. 74) 



94. Hydroeladial internodes theeate and non-thecate 95 



94. Hydroeladial internodes theeate only 98 



95. Nodal septa transverse; supra calyeine and intermediate nemato- 



phores present 96 



95. Nodal septa alternately transverse and oblique; hydroeladia alter- 



nating; hydrotheeae free for half their length P. alieia (p. 75) 



96. Never more than two intermediate internodes; hydrotheca as deep 



as longer diameter, front forming an angle with stem 



P. setaeea (p. 79) 



96. Often more than two intermediate internodes; longer diameter of 



hydrotheca greater than depth, front parallel with stem 97 



97. Septal ridges moderate, usually two on each intermediate inter- 



node P. lagenifera (p. 77) 



97. Septal ridges heavy, never more than one on each intermediate 



internode P. lagenifera septifera (p. 78) 



98. Nematophores monothalamic 99 



98. Nematophores dithalamic : depth of hydrotheca about half its 



greater diameter; gonothecae fusiform P. virginiae 12 



99. Margin of hydrotheca slightly recurved 100 



99. Margin of hydrotheca not recurved; gonothecae on stem or stolon, 



with numerous long spines P. eehinulata 8 



100. Cauline internodes with one to three branches each; gonotheca 

 oval, borne in place of hydrocladium P. goodei (p. 76) 



100. Cauline internodes each with one branch; gonothecae axial, with- 



out spines P. plumularoides (p. 78) 



101. Stem fascicled; hydroeladia branched; no marginal teeth; gono- 



thecae unprotected , Nuditheca 102 



101. Stem simple 103 



102. Hydrotheca without anterior constriction; gonotheca with two or 



three nematophores at base N. dalli 1 ' 2 



103. Gonothecae protected by corbulae, each of which is a modified 



hydrocladium; no hydrotheca at base of each gonangial leaf 



Aglaophenia 104 



103. Gonothecae unprotected; no septal ridges in hydroeladial inter- 



nodes; an anterior interthecal ridge Halieornaria 107 



104. Hydrotheca with 11 irregular teeth A. struthionides (p. 73) 



104. Hydrotheca with 9 teeth 105 



105. Median tooth recurved 106 



105. Median tooth not recurved A. pluma (p. 73) 



106. Hydroeladial nodes well marked; mesial nemataphore reaches 



mouth of hydrotheca A. ineonspicua (p. 72) 



106. Hydroeladial nodes weak; mesial nematophore does not reach 



mouth of hydrotheca A. diegensis (p. 71) 



107. No marginal teeth H. producta (p. 75) 



'. Clark ('76, 1). 8 . Hincks C68). 



-. Nutting ("01, 1). ». Trask ('54). 



3 . Calkins ('99). 10 . L. Agassiz C65). 



*. A. Agassiz ('65). ". Kireuenpauer ('84). 



s . Fewkes CS9). >«. Nutting ("00). 



". Clark { 76, 2). «. Mereschkowsky ('78). 



; . Nutting C99). 



