Vou.2] Hsterly—Copepoda of the San Diego Region. 163 
1. Genus Scolecithrix Brady. 
Undina (in part) Lubbock, 1856, p. 21. 
Scolecithrix Brady, 1883, p. 56. 
Scolecithriz Giesbrecht, p. 337; 1892, pp. 56, 265, 264; 1898, p. 42. 
Lophothriz Giesbrecht, 1895, p. 254. 
Amallophora (in part) Seott, T., 1893, p. 54. 
Neoscolecithrix Canu, 1896, p. 426. 
Scolecithrix Wolfenden, 1904, pp. 119, 120. 
Cephalothorax ellipsoidal, head fused with thorax, abdomen 
of female with four segments, of male with five; anal segment 
commonly short. Anterior antennae in female 19- to 24- jointed, 
in male 17- to 24- jointed, end joints (24 and 25) fused or dis- 
tinet, aesthetasks well developed, more numerous in male. Bitiny 
part of mandible and maxilla rather weak, inner ramus of max- 
illa mostly unsegmented and fused with the second basal. Distal 
bristles of anterior maxilliped thick, soft, in appearance some- 
thing like the aesthetasks of the antennae; these may be vermi- 
form, end in tufts (pencillate), or be pestle-shaped, and are 
usually present in both sexes. Head appendages of male like 
those of the female, but may in special cases be modified in par- 
ticular ways. Outer rami of first four feet 3-jointed, inner 
ramus of first foot 1-jointed, of second 2-jointed, of third and 
fourth 3-jointed; surfaces of both often set with spines and 
points. Fifth foot in female uniramous, 1- to 3-jomted, seldom 
absent; fifth foot of male uniramous on each side, or the left 
biramous and the right uniramous, or both biramous. 
KEY TO SPECIES. 
I JBIGEKCl TANOM CHES poeodcdoudeemoaenoadomacce 5 Ute OmbanO Ow oc 2 
Il, JELeRGh WANN meh (Gi, Zs) Saakaoaccagcocbucb: usoboonoonuUdDe 4 
2. Anterior antennae of female 19-jointed; right of the male 17-, 
acy Wein; TUSHSHOuUMHEh oc benossadcadodobs doa avo nGo cK UMaDUCma od 3 
2. Anterior antennae of female 23-jointed............... S. subdentata 
2. Number of joints unknown; for characters compare description 
anil 306%, BO) cos ona dab ogowoooonpde cas Coo ebe se Gboon nT cor S. pacifica 
3. First joint of outer ramus of first foot with a thorn-like bristle 
Gm Omer mame (NE 26) os eccyo cle crere a ere wie oe ole «wis «els ate ee S. danae 
3. This joint without the bristle ..........2.---.-..-2..-.0> S. bradyi 
4. Anterior antennae of female 23-jointed; fifth foot (fig. 26e) ; 
right antenna of male 17-jointed, left 18-jointed; fifth foot 
(Cie PCED ae poise oo dot SenOie os Ole in Oreo a S. persecans 
