216 DR. J. G. DE MAN ON THE PODOPHTHALMOUS 
@. Lateral margins of the carapace armed with an 
epibranchial tooth. 
122. PorcELtana DEnTata, IL.-Edw. 
Porcellana dentata, M.-Edwards, Hist. Nat. Crustacés, t. ii. p. 251. 
Porcellana bellis, Heller, Crustaceen der Novara- Reise, p. 76, Taf. vi. 
fig. 4. 
Petrolisthes Haswelli, Miers, Report Zoology Voyage of H.M.S. 
‘ Alert,’ 1884, p. 269, pl. xxix. fig. A. 
Fourteen specimens were collected, of which eleven were 
obtained at Owen Island ana three at Sullivan Island. 
I was enabled by Dr. C. Koelbel, of Vienna, to study one of 
Helier’s types of P. bellis, and thus found out that the Mergui 
specimens were specifically identical with it. J then sent one of 
the Mergui specimens to Prof. Milne-Edwards, who informed me 
that it was identical with Porcellana dentata, M.-Edw. Porcellana 
bellis, Heller, is thus a synonym of the latter. No doubt, more- 
over, can be entertained that the Mergui specimens are also 
representatives of P. Haswelli, Miers, from Australia. 
Porcellana dentata, M.-Kdw., presents the following distinc- 
tive characters :—the front is triangular, with the sides a little 
emarginated, rounded anteriorly, and rather much prominent ; 
it is somewhat deflexed, and has a shallow, longitudinal, mesial 
furrow. The gastric region is marked anteriorly, at the base of 
the front, with two transverse linear elevations. The upper 
surface of the carapace is punctate in the middle and posteriorly, 
and marked with delicate transverse lines anteriorly and near 
the sides; these lines, when seen under a strong magnifying- 
glass, appear to be provided anteriorly with microscopical hairs. 
Similar piliferous lines occur also in Porcellana Boscii, but in 
it they are much more visible to the naked eye, and the small 
hairs are also much longer. The lateral margins of the carapace 
are cristate, and terminate anteriorly in the acute epibranchial 
tooth. The chelipedes are almost equal to one another. The 
under margin of the meropodite is armed with a small acute tooth 
about its middle, and the anterior margin terminates in a rounded 
lobe at its external angle. The carpopodite measures nearly ? of 
the length of the carapace, and is nearly twice as long as broad. 
Its anterior margin is armed with five or six teeth; some of 
them, however, are often obsolete, and in individuals not fully 
grown only three or four teeth are found on this margin. The 
