402 Records of the Indian Museum. PVOrEn. xr 
are those made use of in my key to the Indian species (loc. cit. , 
p. 113): the rostrum is longer than in other species of the genus 
and is provided with an elevated dentate basal crest; the telson is 
lanceolate, with the apex acute and unarmed. 
These characters appear to me to be altogether unsuitable for 
generic definition and are clearly of far less morphological value 
than those hitherto employed in the generic subdivision of the 
family. In young specimens of H. ensirostris there is a pair of 
long spines at the tip of the telson, reaching far beyond the pro- 
duced median point and these may still be seen in a reduced con- 
dition, even in individuals 40 mm. inlength. Stebbing also, when 
describing Exhippolysmata tugelae, notes the presence of a very 
small spine on either side of the telson tip. The claims of Exhip- 
polysmata to generic rank rest therefore on the rostral characters 
and in the fact that the telson has a median point instead of being 
rounded. If it be retained, its recognition requires to be balanced 
by the institution of aconsiderable number of other ‘‘ new genera,’’ 
a procedure which seems unlikely to serve any useful purpose, 
while tending to confuse the natural affinities of the component 
species of the family. 
Lysmatella, recently instituted by Borradaile for a species 
from the Maldives, is based on surer structural differences, but is 
none the less very closely allied to Hifpolysmata. In the very 
brief preliminary diagnosis that Borradaile has given,' it is merely 
described as ‘‘ related to Lysmata, but without mastigobranchs on 
the legs.” The type species of the genus, Lysmatella prima, is 
described in the same paper. 
Three specimens, recently obtained in the Andamans, agree 
in every particular with the generic and specific descriptions that 
Borradaile has given; but, unfortunately, the information is so 
meagre that it is impossible to be certain of their identity. The 
Andaman specimens are, however, clearly related in a very close 
manner with the species of Hippolysmata belonging to the vittata 
group, the affinity being shown not only by the almost exact 
correspondence in all structural details (except for the absence of 
epipods), but also in colour, the specimens when alive exhibiting 
the brilliant longitudinal red streaks that characterise H. vittata 
and H. dentata. 
If my identification of the Andaman specimens is correct it 
appears to me unwise, in the present state of our knowledge, to 
recognise Lysmatella in full generic significance. The presence or 
absence of epipods is in many cases a valuable aid to generic 
diagnosis in the Hippolytidae, but the number of these structures 
is variable in the genera Spevontocaris and Latreutes and in Hip- 
polysmata ensirostris the entire series is rudimentary. In many 
species referred to Hippolysmata the epipods have not been ex- 
amined and, on analogy with other genera, it would occasion no 
surprise if some were found to possess a reduced number. 

1 Borradaile, Ann. Mag. Nat. Hist., (8S), XV, p. 206 (1915). 
