426 
ZOOLOGY OF THE FAR KAvST. 
protopodite, and a small distal joint, the endopodite, with a strong plumose seta at 
its base on the outer corner of the basipodite. The form depicted by Dana, in which 
both endopodite and exopodite are present, is confined to the genera Glyptonotus, 
Chiridotea, M acrochiridoihea , and Mcsidotca. It seems almost certain that Dana 
was in error on this point, but the matter is one that wants clearing up before 
the status of the genus Cleantis can be satisfactorily settled. 
Further with regard to the maxillipede, Dana only figures three joints in the 
palp. Here again Dana is probably in error, but it is most important to know how 
many joints there are in the palp of the type species, for this character is of first 
value for the classification of the species into genera. 
Two other characters in Dana's definition of the genus deserve special mention. 
The flagellum of the antennae is uni- articulate and the fifth pair of thoracic limbs is 
conspicuousl}^ shorter than the remainder. 
It will be recognised, therefore, that for two important characters, the palp of 
the maxillipedes and the form of the uropods, our information with respect to the 
type species of Cleantis is deficient or of doubtful accuracy. 
It is clear that if Dana's description is borne out by subsequent examination of 
the type species, none of the species referred to the genus by later authors can 
remain within its limits. If Dana was in error on the two characters named, what is 
the extent of his error ? 
It is now necessary to consider the species referred to the genera Cleantis and 
7jenobiana. 
The genus Zenohia was instituted by Risso in 1826 for two species, Zenobia 
prismatica and Zenohia mediterranea both of Risso. These two species have since 
been shown to be synonymous. Miers, (1881) in his revision of the family treats 
Zenohia as a subgenus of the genus Idotca, characterised as follows:--" Post-abdomen 
composed of four or five distinct segments, visible in a dorsal view, (species small, 
or minute, with a few-jointed antennal flagellum). Zenobia ? " To this sub-genus, 
as thus defined, Miers refers both species of Risso and two new ones, Idotea {Zenohia) 
whymperi, Miers, and /. (Z.) danai, Miers. 
DoUfuss (1895) restored Risso' s name to full generic rank and in the same year 
Stebbing pointed out that the name was preoccupied and changed it to Zenobiana. 
No other species of the genus have been described as such, but Issel (1913) 
definitely regards the genus Cleantis of Dana as a synonym and refers to all the 
species of Cleantis as species of Zenobiana. Bate and Westwood expressed very 
much the same opinion and in 191 1 I pointed out that if this opinion was accepted, 
Dana's name had priority. 
The following species of the genus Cleantis have been described subsequent to 
the type species, C. linearis, Dana : — 
C. planicauda, Benedict. C. heathii, Richardson. 
C. tubicola, G. M. Thomson. C. occidentalis, Richardson. 
C. granulosa Heller. C. strasseni, Thielemann. 
C. isopus, Miers. C. japonica, Richardson. 
