The Osteology of Dallis pectoralis. 261 
When only two tooth bearing pharyngeals are present one of them 
represents the anchylosed pharyngeals of two arches. 
3. The upper limb of the posttemporal attached to 
the epiotic by a ligament. 
This character is common to Umbra and Lucius, but is also 
found among several soft rayed fishes of other orders. So far as 
they have been studied the members of the Iniomi, Heteromi, and 
Lyopomi are known to have it.!) 
4. The palatine pterygoid arch reduced to a single 
element. 
This is a character of neither Umbra nor Lucius, but of members 
of the Poecillidae, another family of the order Haplomi. 
5. The splanchnic anatomy is very similar to that 
of Umbr.a. 
They differ in no essential particular. 
Diagnosis of characters of Dallia pectoralis. 
Cranium with much of the primordial cartilage remaining; ali- 
sphenoids, orbitosphenoids, basisphenoid, opisthotics, supraorbitals and 
suborbitals absent; a paired dermal ethmoid overlying the unossified 
ethmoidal cartilage; occipital condyle confined to the basioceipital; 
interorbital membrane double and widely separated; supraoceipital 
without a developed crest; prootie not pierced for passage of fifth 
and seventh nerves; pterygoid absent, the palatine attached directly 
to the quadrate and mesopterygoid; maxillary and premaxillary 
closely attached to each other but not anchylosed; the hyper- and 
hypocoracoids represented by a solid plate of cartilage, the actinosts 
by a thin divided fringed plate; shoulder girdle not joined to eranium, 
but laterally braced by first rib; no mesocoracoid ; superior pharyngeals 
all present and separate, the posterior two only bearing teeth; lower 
pharyngeals separate; teeth on vomer, palatines and premaxillary; 
all of the abdominal vertebrae bearing ribs; no epipleurals present: 
parapophyses present on all abdominal vertebrae, only the posterior 
three or four anchylosed to vertebral centra; spines of last five 
1) “The character of having the scapular arch free from the cranium 
and attached to the anterior vertebrae, shared by these fishes [the Heteromi] 
with the eels and several other groups may be, in the different cases, of 
independent origin, and is probably not indicative of any special affinity.” 
GILL, in: Amer. Naturalist, Nov. 1889. 
