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MAYDEN ET AL.-SYSTEMATICS OF WESTERN CYPRINIDS 831 TABLE 7. SYNAPOMORPHIC CHARACTERS THAT IDENTIFY MONOPHYLETIC GROUPS WITHIN THE GENUS Ptychocheilus. Ptychocheilus umpquae is represented by the Umpqua drainage population. Characters are those listed in Table 1. Character State change Monophyly of Ptychocheilus: I. Prepectoral length/SL 0 to 1* 7. Dorsal origin to pelvic insertion/ SL 2to1 14. Dorsal insertion to anal origin/SL 2 to 1 26. Pelvic fin length/SL 1 too 27. Pectoral fin length/SL 1 to 0 32. Occiput to opercular cleft/PPL I to 0 33. Opercular cleft to opercular cleft/ PPL 2 to 1 35. Left opercular cleft to right pec- toral insertion/PPL 1 to 0 39. Left supraorbital to left pectoral insertion/PPL 1 to 0 42. Left pectoral insertion to left max- illa/PPL 2 to 1 43. Left pectoral insertion to right maxilla/PPL 2 to 1 44. Maxilla to snout tip/PPL 0 to 1 45. Lower jaw length/PPL 1 to 2 Monophyly of P. umpquae + P. grandis + P. lucius: 11. Dorsal origin to anal origin/SL 1 to 0** 13. Dorsal insertion to pelvic inser- tion/SL 2 to 1 44. Maxilla to snout tip/PPL 1 to 2 Monophyly of P. grandis + P. lucius: 19. Upper c.p.r.*** base to anal in- sertion/SL I to 0 20. Upper c.p.r. base to lower c.p.r. base/SL 1 too 43. Left pectoral insertion to right maxilla/SL 1 too 44. Lower jaw length/PPL 2 to 3 *Character state reversal in P. lucius. •'Character state reversal in P. grandis. •'• Abbreviation: "c.p.r" = caudal principal ray Lake, which now drains directly into Silt- coos, seems to have the best population. In historic times, Woahink drained to some- where on Siltcoos River close to the ocean, but was diverted when the coast highway was built.... there is difficulty in telling whether the lakes have a fauna derived nat- urally through some old connections with the Siuslaw, the Umpqua, or both, or through introductions, or from a combi- nation of the possibilities. Given Bond's reservations regarding the or- igin of squawfishes inhabiting the lakes and coastal drainages between the Siuslaw and Umpqua, the characters of the "Siuslaw" sam- ples or any samples from the drainages other than the Umpqua should be interpreted with caution. For now, because the Umpqua River supplied the type specimen, the species name umpquae would apply with certainty only to the Umpqua population. Additional study of spec- imens from the Siuslaw River proper and other coastal populations, involving both biochemical and morphological evaluations, will be neces- sary to test Bond's hypotheses, before definitive statements can be made regarding their taxo- nomic status and relationships. Plychocheilus oregonensis, P. umpquae (Umpqua drainage), and P. grandis are phenetically sim- ilar (Fig. 2), which may have led Moyle (1980a) to consider the three species to be closely re- lated. These similarities, however, represent re- tained-primitive features developed in the an- cestor of all species of Plychocheilus (Fig. 5) and are not indicative of relationships. These three taxa formed a basal paraphyietic assemblage in our Wagner Tree (Fig. 5) and did not compose a monophyletic group. These relationships sup- port Holden's (1980) hypothesis of a sister-group relationship between P. grandis and P. lucius. The relationships within the genus Plychochei- lus (omitting the problematic Siuslaw popula- tion) are consistent with a north-to-south pattern of speciation within the genus. Such divergence could result from a step-wise southward expan- sion of an ancestral northern form, punctuated by vicariant speciation events. Alternatively, it may be viewed as a single, widespread ancestor separated by a series of vicariant events that, coincidentally, followed a north-to-south se- quence of occurrence, or a combination of the two scenarios. Our interpretation of relationships within the genus Plychocheilus differs from that suggested by Carney and Page (1990). Their and our un- rooted networks of relationships are equivalent; however, we differ in regard to the placement of the root. Carney and Page acknowledge this rooting problem: "Outgroup comparisons us- ing species smaller than P. lucius and with lower meristic counts (i.e., all other North American minnows except certain species of Gila) yield a phylogeny with P. lucius and P. grandis as de- rived sister taxa and P. oregonensis and P. umpquae as ancestral. Conversely, outgroup comparisons using species with higher meristic counts (e.g.,