672 ALLIS. (Vor. XII. 
branchial, and somewhat, also, on the bone beyond it. The 
latter (dab.V) arises from the ventral surface of the thin 
projecting corner of the triangular cartilaginous cap of the 
fourth ceratobranchial, and is inserted on the dorsal surface of 
the cartilaginous cap of the fifth ceratobranchial, a portion of 
its fibres passing over the end of the cartilage and there con- | 
tracting into a tendon which is, in part, inserted on the ventral 
surface of the cap, or of the bone adjoining it, and in part is 
continuous with the outer, posterior, tendinous end of the 
transversus ventralis posterior. 
The adductores are each innervated by the nerve of its arch, 
the branch that innervates it passing in each case over the 
posterior edge of the arch. 
5. Interarcuales Ventrales. 
The muscles belonging to this group in Acipenser are called 
by Vetter (No. 125, p. 478) the interarcuales ventrales, although 
but one of them, the first one of the group, is in any way 
interarcual. In teleosts Vetter retains the same name for the 
group (No. 125, p.517), but subdivides it into two portions, the 
obliqui ventrales and transversi ventrales. _McMurrich (No. 76, 
p. 132) retains for the obliqui muscles in Amia (doubtless 
because Amia is a ganoid) the name given by Vetter to the 
corresponding muscles in Acipenser, and so separates the 
muscles in Amia into two groups, the interarcuales ventrales 
and transversi ventrales. The names given by Vetter to the 
muscles in teleosts seeming also the more appropriate for those 
in Amia, I have used them instead of the ones selected by 
McMurrich. 
a. Obliqui Ventrales. 
The obliquus ventralis of the first arch (Ov./, Fig. 47, 
Pl. XX XIII) arises in the groove on the ventral surface of the 
first hypobranchial, the surface of origin occupying the full 
extent of the groove from the bend near the anterior end of 
the bone to its hind end. Most of the fibres of the muscle 
converge proximally, that is, outward and backward, toward 
the middle line of its under surface, and are there inserted on 
