NECTURUS MACULATUS. 425 



part described by Huxley as the stapedio-suspensorial ligament. Certainly no definite 

 ligament, the fibers of which extend between the operculum and the quadi'ate, can be 

 demonstrated. 



In this connection it is interesting to compare the work of other writers on the sub- 

 ject, who have naturally been infiuenced by the description given by Huxley. W. K. 

 Parker ('77, pi. 28, fig. 5) has figured this region in detail in Proteus. This shows the 

 same broad connective ti.ssue band first described, but no definite stapedio-suspensorial 

 ligament. This band, which appears identical with that which I have described in 

 Necturus, is lettered " .st. si.," but no mention is made of it in the text. The two other 

 ligaments are as in Necturus, if one counts the two mandibulo-hyoid ligaments as one. 

 Wiedersheim ('77) accepts Huxley's statements and quotes them (paraphi-ased, p. 435). 

 He speaks of a lig. stapedio-suspensoriale in Proteus, but in his figure 19, in which he 

 refers to this ligament as " Prop," he really points out the bony connection between 

 operculum and paraquadratum, showing that he has confused the two, perhaps for the 

 moment. His figure of Proteus is in reality like W. K. Parker's, and well expresses the 

 condition in Necturus. 



The Free Sense Capsules. 



The nasal capsules and the sclera of the eyes receive a more or less complete rein- 

 forcement of cartilage, which is structurally a skeletal part, and may be considered under 

 the heading given above. 



The nasal capsules are somewhat in the shape of round-bottom flasks with necks 

 curved outwards, and they he upon the sides of the anterior angle of the skull, extending 

 from the alveolar processes of the premaxillaries to the antoi'bital processes. The nostrils 

 or anterior nares appear at the end of the outwardly curved necks and are hence diver- 

 gent from one another and situated upon the sides of the blunt snout with a wide inter- 

 space. The posterior nares lie undei'neath, near the rounded posterior end, and in close 

 connection with the anterior margin of the antorbital processes which are curved some- 

 what around them. The sides and roof of each capsule are covered by a delicate reti- 

 cular or fenestrated cartilage of a soft consistency and rather difficult of demonstration as 

 cartilage. 



A very similar structure is found in Proteus, where it was first described by Leydig, 

 in 1853, (quoted by Wiedersheim, '77) and the form in Necturus appears to have been 

 first shown by Wiedersheim, in 1877, who both describes and figures it with great clear- 



