Mysidacea, Tanaidacea and Isopoda. 427 
In addition, Miers, 1881, referred three species to the genus, which have since 
been placed in the genus Erichsonella, Benedict { = Enchsonia, Dana) and do not 
concern us here. 
Of the above eight species of Cleantis, C. isopus, Miers has since been made the 
type of anew genus Clcantiella, Richardson, by reason of the "differences in the 
shape of the body, which is broader and more flattened, and in the character of the 
legs, and to the fact that the abdomen is composed of but two segments." 
It will be useful to set out in tabular form the characters of the species of 
Cleantis, Clcantiella and Zenobiana, as regards the palp of the maxillipedes, the 
segmentation of the metasom.e and the flagellum of the antennae. 
Joints in 
ULiv U U f 
Maxillipede. 
M etasome. 
Segments. ] Sutures. 
Flag, of 
Antennae. 
Zenobiana :— 

prismatica , Risso . . 
5 
4 
I 
J 1-4 
^ I ? 
whymperi, Miers . . 
4 
0 
I 
danai, Miers 
5 
? 
2 
Cl.EANTIS : — 
linearis, Dana 
3 ? 
3 
I 
I 
planicauda, Benedict 
5 
4 
T 
I 
japonica, Richardson 
5 
4 
I 
I 
occidentalis, Richardson 
4 
4 
I 
I 
heathii, Richardson 
4 
3 
I 
3 
granulosa, Heller . . 
4 
5 
? 
I 
strasseni, Thieleman 
4 
I 
.) 
,S 
/7/ft?cf)/rt, Thomson. . 
ClEANTIRLLA : — 
isopus, Miers 
5 
2 
2 
I 
Apart from the uncertainty about the number of joints in the maxillipede palp 
in Cleantis linearis, Dana, we see that the remaining species in the above table have 
either four or five joints in this appendage. Tliis difference has been u.sed as a 
generic character in other members of the family. 
The segmentation of the metasome and the number of sutures representing 
incomplete segments show the greatest diversity and, if this character is also to be 
used to separate genera, only two in the above list of species could be referred to the 
same genus, Cleantis planicauda and C . japonica and a new genus would be required 
for each of the other species ! 
