434 
PACIFIC SCIENCE, VoL VII, October, 1953 
Fig. 27. Larval form of Coronida sp. a. Dorsal aspect 
of coroniderichthus larva; b, second, first, third, fourth, 
and fifth thoracic appendages; c, first abdominal ap- 
pendage. 
ing the summer. Larvae resemble lysioerich- 
thus in shape of thoracic appendages, but 
with raptorial dactylus slightly inflated at its 
base; propodus of fourth thoracic appendage 
rounded, nearly twice as large as that of fifth 
which is rectangular; all abdominal append- 
ages present; no gills; telson rectangular as 
in most larval forms, bearing two denticles 
between submedian and lateral denticles; uro- 
pods present, outer margin of exopod armed 
with three spines, basal portion elongated 
into two spines, outer longer than inner. 
Specimens measure 10.0 to 14.5 mm. from 
the tip of the rostral spine to the posterior 
margin of the telson. 
Figures 26d, e represent the first postlarval 
stage of this species which is found in nearly 
equal numbers with the previous stage. Only 
the carapace and anterior segments and the 
raptorial claw have been illustrated as all other 
structures are the same as those seen in the 
preceding stage. The inner margin of the dac- 
tylus is armed with ten teeth. There is no 
distinct increase in size over that of the last 
larval stage. These forms may be larval stages 
of C. sinuosa, but the larval structures bear 
no resemblance to diagnostic characteristics 
of this species. Apparently the species to which 
these larvae belong is quite common, al- 
though it has not been found as yet. 
Coronida sp.^ 
Fig. 21a-c 
Five coroniderichthus larvae measuring 18 
to 20 mm. from the tip of the rostral spine 
to the posterior margin of the telson were 
collected at Kawaihae, Hawaii. The append- 
ages indicate that they belong to some species 
of Coronida, but no adult specimens have been 
found which have the same characteristics as 
those possessed by this larval stage. I believe 
that the first postlarval stage would appear 
at the next molt because the facies of the 
adult carapace, telson, and raptorial dactylus 
show through the very clear chitin. These 
specimens are unique in that the larval cara- 
pace covers all but the last two abdominal 
somites and the telson, and the median an- 
terior spine and posterolateral spines are 
greatly elongated. This condition is not found 
in any other larval form, hence it should 
serve as a diagnostic character for the separa- 
tion of this larval form from others belonging 
to this genus. 
Odontodactylus sp.^ 
Fig. 28^-^ 
Eight odonterichthus larvae, ranging in 
length from 18 to 35 mm., were taken in a 
plankton tow in the Molokai Channel. They 
resemble pseuderichthus larvae very much, 
and it is possible to distinguish the two only 
