148 University of California Publications. [ ZooLoGy 
to be distinct from the latter in bearing an articulating process 
on the second joint of the outer ramus of the left foot. There is 
a muscle attached to the process which serves to move it. 
The relative lengths of the rami of the posterior antennae dis- 
tinguish the animals from Fuchirella, as does the division 
(though indistinct) of the outer ramus of the first foot into 
three joints. In Euchaeta, the outer ramus of the first foot is 
distinctly 3-jointed in the male, and the rami of the posterior 
antennae are about equal in length. In several female speci- 
mens also the outer rami of the first feet are indistinctly divided 
into three joints, and the sexes correspond in this respect. 
Sars (1900, p. 59-63) has deseribed the male and female of 
Undeuchaeta spectabilis. So far as I know, his is the first record 
of the male of the genus. In his specimens the anterior antennae 
of the female are 24-jointed, while in Giesbrecht’s the number of 
joints is 23. In his description of the male, Sars gives the num- 
ber of joints of the anterior antennae as 22, but in his drawing 
(pl. 16, fig. 2) there are but 21. The fifth pair of feet in the 
male of U. spectabilis is very different from that in the San 
Diego specimens, a striking point being that both the right and 
left feet are biramous. 
The description of the male of the genus given above is based 
upon the San Diego specimens. 
1. Undeuchaeta major Giesbrecht. 
Euchaeta australis Brady, 1883, p. 65, pl. 21, figs. 5-11. 
Undeuchaeta major Giesbrecht, 1888, p. 336; 1892, pp. 227, 232, 
pl. 37, figs. 56, 57, 59; 1898, p. 34. 
2 Head with median crest, genital segment with protrusion on 
right side and a hooked pointed appendage at the right of the 
genital opening (fig. 16a). 
& (new) Compare generic description. 
Coloration: Female not especially transparent, with red pig- 
ment on basals of posterior maxillipeds, and in mouth region. 
Male: plumose bristles of furea steel-blue; those of posterior 
antennae and mandible red; on the feet the bristles are faintly 
red on the outer ends. 
‘— }. 2 ee a ee ees 
