Vou.2]  Esterly—Copepoda of the San Diego Region. 151 
posterior maxilliped slender. Spines on second basal of fourth 
foot unusual. Right foot of fifth pair biramous, with forceps; 
left stylet-like, with rudimentary inner ramus. 
KEY TO SPECIES. 
Brisa] ihe SE CUO) Pget2 C1S( 8) eet tase RE Red, Cates ae ee ye ee ea io) 
BE UEt Mab OGRE EESCIIE. 55 'crctae A rales cha dirceaeta cme rermeiies am Na cast wares aus 4 
Q1. Head without crest, and rostrum one-pointed (fig. 19a) ........ 2 
[Head wath erest, rostrum present (figs 200)06 $4.06 vs. 0secks ooo a 
2. Outer ramus of posterior antenna about twice as long as inner.. 
POCAIDToOOoGoOCGoDonObDoOOOooCoO DTU o OOO OOo DUM COO OC Haga nS E. rostrata 
2. Outer ramus nearly four times as long as inner (fig. 20c)........ 3 
3. Genital segment with long sac-like appendage on left side (fig. 
HSE) Spire ny so RSRee PS cc sroy he cts enc ec OAR GNS SoS] gears Mtaton fl ohare es crer ance E. messinensis 
a Heaiewat he low erest (fe 20M) sa. ca catia ers sree) saa eee a, E. pulchra 
a Eleagewith iioh Cresta (Ho. 226)... vtec eo oe8.s Cccass ss he ene E. galeata 
@ JAG aA NONy Cressy (Ge PASO) Geis Gwomue bon GomoG oes onoood Gone 2 
Meade wabhOut seresben(He: ZUG) jf. 2 sr. sis: oj eieiord-csceve: srnlelenet sue tere jacsichals 8 ats 3 
2. Forceps-like terminal portion of right fifth foot longer than the 
JORISEUL joronron@in, (Galery ISA) s Gagaccncoucace Ruste cet ekareeMenene E. messinensis 
2. Terminal portion (forceps) of right fifth foot shorter than the 
ORAL TNOMaON, Ciey HUM), aeiocs Secoonadaudoo bongo otas E. pulchra 
3. Fifth foot short, the right about four times as long as the second 
basalts: broad Chios 20) oo ysncla erstcetsl arses cistla dita ehs vec. ee & E. amoena 
3. Right fifth foot six times as long as the second basal joint. .E. rostrata 
1. Euchirella messinensis Claus. 
Undina messinensis Claus, 1863, p. 187, pl. 31, figs. 8-18. 
Euchirella messinensis Giesbrecht, 1892, pp. 232, 244; pl. 15, figs. 
12, 16, 21, 24; pl. 36, figs. 14, 15, 18, 24, 25; 1898, p. 35. 
2 Forehead with rostrum, without crest (fig. 18a); genital 
segment asymmetrical, with sac-like appendage on left side of 
dorsal surface (fig. 18) ; third terminal bristle on right side of 
furea elongated. Inner ramus of posterior antenna 14 as long 
as outer, second joint of former with 5-4 bristles. First basal 
of fourth pair of feet with one or two spines on inner border, 
the longer of which reaches beyond the end of the joint. 
4 Forehead with a low and rather long crest (fig. 18c) ; fifth 
foot slender, the right foot (fig. 18d) over seven times as long 
as the second basal is broad, the forceps longer than the basals. 
Coloration: Not very transparent; red pigment in body and 
on bristles of posterior antennae, and basals of swimming feet. 
Leneth: Female, 4.5 mm.; male, 4 mm. 
