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Psyche 
[Vol. 95 
Methylini-Hydrovatini cannot be conclusively resolved and the 
phylogeny in Wolfe (1985) should be adjusted. At best (Fig. 3B), 
structural data indicates Laccornis is the most plesiotypic clade fol- 
lowed by a polychotomy that includes Laccornellus, Canthyporus, 
and Methlini-Hydrovatini. Most characters indicate Bidessini and 
Lioporeus are more plesiotypic than remaining hydroporines. How- 
ever, the primary characters suggesting this are either variable or 
gradational; although character trends are evident it is difficult to 
polarize these characters (e.g. internal elytral ridge, mesotibial 
spines) on a node by node basis. 
It seems that the best hypothesis for now is that of Fig. 3C, at 
least until immature stages of Lioporeus and Laccornellus are de- 
scribed and/or more synapotypies are discovered. For example, if 
members of Lioporeus, Laccornellus, and/or all had distinctly long 
urogomphi, I would be more confident about using that character 
as a synapotypy to separate Canthyporus etc. from Methlini- 
Hydrovatini-Laccornini. Further resolution of phylogeny of hydro- 
porines will require analyses emphasizing more African and 
Australian genera so that an alternate hypothesis involving inde- 
pendent evolution of the northern and southern hemisphere 
hydroporine faunas can be investigated adequately. 
Summary 
The eighth abdominal tergum of rpost hydroporines is evenly 
convex posteriorly and ventrally is folded inward for about 0.25 the 
length of the tergum. On males and females of Hydrovatus and 
Methlini ( Celina and Met hies ), tergum 8 is posteriorly acute and 
consists of a dorsal and ventral lamina that are about equal in size. 
In methlines, terga 7 and 8 are modified. On tergum 8, the dorsal 
lamina additionally is modified posteriorly into a distinct, trifid, 
highly sclerotized, spearlike structure with two long, diverging, an- 
teriorly extended apodemes. Shorter anteriorly extended apodemes 
also are present on the anterior edge of tergum 7. These modifica- 
tions suggest that Hydrovatus and Methlini form a monophyletic 
unit and also support the contention that Methlini (which includes 
Celina and Methles) is monophyletic. Specimens of Queda com- 
pressa do not possess these distinctive abdominal modifications and 
that genus may be improperly assigned to Hydrovatini. 
