20 University of California Publications. [zoology. 



30. Stem geniculate, pedicels taking the place of stem joints; gono- 



thecae annulated, with annulated pedicels H. speciosum 2 



31. Branched, li inches high; hydrothecae on internodes sessile, not 



reaching beyond distal node; rim not everted ...H. kofoidi (p. 49) 



32. Densely and irregularly branched, often three branches from same 



shoulderlike process; hydrothecae sub-alternate, rim everted 



H. densum :! 



32. Bushy, principal branches pinnate; rim of hydrothecae not 

 everted; gonotheeea ovate, female surmounted by two hydranths.. 

 H. haleeinum' 



32. Stem and branches polysiphonic, stiff; hydrothecae everted; gono- 

 thecae compressed, spiny H. muricatum s 



32. Each internode of branches with one or two proximal annulae, with 

 distal hydrothecae reaching beyond end of internode; ultimate 

 branches geniculate H. nuttingi (p. 50) 



32. Flabellate colony; hydrauth small, 20 tentacles, pedicels from 

 proximal part of internode H. reversurn 2 



32. Thick stem and branches fascicled with many tubes, branching 

 profusely; hydranths numerous, crowded, in whorls and clusters, 

 with 10 tentacles; rim of hydrotheca non-everted H. robustunr 



32. Stout, coarse, ultimate branches divided into wedge-shaped inter- 

 nodes: gonotheeae with orifice on one side... H. scutum" 



32. Hydrothecae everted ; male gonotheca a circular disk, with peduncle 



with one or two annulae H. wilsoni 1 



33. Non-operculate 34 



33. Operculate; operculum of numerous small triangular pieces 58 



34. Gonophores sessile ; sporosacs Campanularia 35 



34. Gonophores sessile, medusoid Gonothyraea 48 



34. Gonophores free medusae 49 



34. Hydrothecae tubular, smooth margin, hydranth with conical pro- 



boscis Hebella 57 



35. Stems branched 36 



35. Stems unbranched 42 



36. Stems fascicled 37 



36. Stems simple 40 



37. Pedicels of hydranths in whorls of 4 to 6, at regular intervals 38 



37. Pedicels of hydranths alternating in one plane 39 



38. Hydrotheca with 10-12 blunt denticles; base rounded C. circula 1 



38. Hydrotheca with 12 sharp denticles; tapering to base 



C. verticillata K 



39. Colony often 200 mm. long, densely branching; hydrotheca with 



10 bicuspid teeth, hydranth with 26 tentacles ...C. pacifica (p. 53) 



39. Colony 5-10 mm. long; hydrotheca with 11-12 moderate teeth; 



hydranth with 20-24 tentacles C. fascia (p. 52) 



40. Colonies small, with few branches, which are parallel to the parent 



stem _ 41 



40. Hydrotheca small, funnel-shaped, with even rim C. exigua 8 



40. Stems unbranched except for the hydrotheca pedicels, which are 



short and regularly alternate, giving the colony the aspect of a 

 Sertularian C. rigida 4 



41. Length of hydrotheca, .65-1.00 mm. ; breadth, .36-. 45 mm.; 14-15 



teeth on margin C. denticulata (p. 51) 



41. Length of hydrotheca, .5 in.; breadth, .25 m. ; margin with 9-10 

 teeth C. attenuata 3 



