132 MR. E. PHELPS ALLIS, JUN., OX 



these supplementary secondary lower and upper lips. The ante- 

 rior end of the anterior process of the mandibular labial gives 

 insertion to a tendon of the musculus levator anguli oris pos- 

 terior, that tendon passing downward across the internal surface 

 of the labial to reach its point of insertion, as shown in Luther's 

 figure of Chimcera monstrosa. Connected with this tendon, and 

 as direct ventral continuations of it, there are two small liga- 

 ments, one of which joins the ligament I of Luther's descriptions, 

 to be described immediately below, while the other runs ventro- 

 mesially along the external surface of the mandibula, internal to 

 the musculus labialis posterior, and has its insertion in tough 

 fibrous tissues in the median line. The tendon of the musculus 

 labialis posterior runs dorsally along the internal surface of the 

 mandibular labial, internal (mesial) to the tendon of the muscului? 

 levator anguli oris posterior, and has its insertion on the internal 

 surface of the mandibular labial near its dorsal end, this also being 

 as shown in Luther's figures of Chimcera monstrosa. 



The cartilage a of Hubreeht's descriptions was considered by 

 him to be, together with a related " Bandapparat," the homologue 

 of the mandibular labial of the Selachii. Vetter does not men- 

 tion this cartilage. K. Flirbringer accepts Hubreeht's statements 

 regarding it as correct. Luther considers this cartilage, alone, 

 to be the homologue of the mandibular labial of the Selachii, 

 and, following Gegenbaur's nomenclature, he calls it the pre- 

 mandibular labial. The Bandapparat he considers to be an 

 independent and superficial structure, and he fully describes it 

 in Ghirtuera inonstrosa. 



In Chimcp.ra colliei, the thick lower lip contains a mass of dense 

 tough fibrous tissue which extends the full length of the lip and 

 from its oral edge a eei'tain distance posteriorly. This mass of 

 tissue completely surrounds the musculus labialis posterior, that 

 muscle traversing a canal-like perforation of the posterior poition 

 of the tissue without being in any way attached to it excepting 

 only at its origin near the symphysis of the mandibles. The 

 anterior (oral) end of the cartilage a is strongly attached to this 

 tough fibrous tissue, and it abuts against the posterior surface of 

 the musculus labialis posterior, the cartilage being grooved to 

 receive the muscle and the edges of the groove sometimes pro- 

 jecting to such an extent that the cartilage is decidedly Y-shaped. 

 External to the symphysial edge of the cartilage, and strongly 

 attached to it, there is a small piece of strongly calcified cartilage 

 which is grooved on its external surface to lodge a section of the 

 mandibular latero-sensory canal. On its symphysial edge the car- 

 tilage a gives origin to ligamentous tissues which cross the median 

 line and are attached to the corresponding cartilage of the oppo- 

 site -side, this apparently being as shown in Luther's figure of 

 Chimcera inonstrosa, but the musculus labialis inferior of that 

 author's descriptions of Chivnccra mooistrosa is not found in my 

 specimens of Chimcera colliei. 



The ligament I of Luther's descriptions (1909 i, fig. 28) in 



