DEVELOPMENT OF THE AURICLE IN THE HUMAN EMBRYO. 



123 



Helix mandibularis [Gradenigo]. Fold found in the 

 embryo directly in front of the third auricular 

 hillock and extending down in front of the second 

 and first hillocks. According to Gradenigo, this 

 fold gives origin to the anterior end of the helix, 

 crus helicis, and tragus. 



Helix posterior [Schwalbe]. That portion of the helix 

 derived from the hyoidal arch. Same as helix 

 hyoidalis [Gradenigo]. 



Incisurae carrilaginis meatus auditorii externi [San- 

 torini]. Clefts in cartilage of external meatus, 

 somewhat analogous to the clefts between the 

 cartilaginous rings of the trachea. 



Incisura intertragica. The cleft between the tragus 

 and antitragus. A derivative of the lower end 

 of the first branchial cleft. 



Lamina tragi. Cartilaginous plate supporting tragus. 



Lingula auriculae [His]. See Cauda helicis. 



Lobulus auriculae. The free edge of the auricle below 

 the antitragus continuous with the scapha helix. 

 See Helix. 



Margo oralis helicis [Baum and Dobers]. Anterior free 

 border of auricle, particularly in such animals as 

 the pig. In a similar way the posterior border is 

 referred to as aboral. 



Pars articularis conchae. The upper half of the 

 concha. It includes the two articular fossa? 

 (eminentise), plica principalis, crus helicis, and 

 spina helicis. (See figs. 1 and 2.) 



Plica auricularis longitudinalis cranialis [Henneberg]. 

 The most cranial of the three longitudinal folds 

 of the scapha in such animals as the pig. The 

 others are designated medialis and caudahs, 

 respectively. 



Plica principalis [Boas]. Equivalent to crus inferius 

 ii a I helicis. Introduced because it is more accu- 

 rately applied, particularly to the auricle of mam- 

 mals other than man. 



Ponticulus. Ridge on inner surface of conchal car- 

 tilage downward from the inferior articular 

 eminence. It appears to be concerned with the 

 ligamentous attachment of the auricle. 



Posteron [Boas]. See Anteron. 



Rima helicis [Albums]. Perforation of the cartilage of 

 the crus helicis. 



Satyr-tip [Schwalbe]. The, tip of the auricle toward the 

 crown of the head. Also called crown-lip or 

 crown-angle. 



Scapha. Concave surface of the free portion of the 

 auricle lying between the anthelix and the helix. 

 Term applied by Henneberg to the entire free' 

 auricle from the anthelix to the free border. He 

 applies the term helix to the unwrinkled border 

 of the scapha. 



Scapha primitiva [Henneberg]. Same as free ear-fold. 



Scutellum. See Scutulum. 



Scutulum. (Also known as scutellum, carlilago- 

 scutiformis, or cartilago-sculularis.) This is sup- 

 posed by some writers to be simply an enlarged 

 spina helicis which has become detached. Ac- 

 cording to Schmidt, it is an accessory cartilage, 

 connected with the complicated muscular appa- 

 ratus, which is provided for the auricle of some 

 mammals and is entirely absent in man. See 

 Spina helicis. 



Spina helicis. Cartilaginous process extending forward 

 from the pars articularis concha;. (See fig. 1.) 

 It is not in reality a part of the helix. It is sup- 

 posed that this structure is enlarged and becomes 

 detached in some mammals to form the scutulum. 



Tsenia lobularis. The fold attaching the lobule to 

 the parotid region. In the embryo it appears 

 before the lobule itself, being derived from the 

 ventral end of the hyoid bar below hillock 6. 

 It is the extension and widening of the tenia as a 

 free fold, to join the lower end of the helix, that 

 produces the lobule. 



Torus marginalis, or Randwulst [Henneberg]. The 

 rounded border inclosing the fossa angularis. 

 It makes its appearance as the hillocks disappear. 

 The latter contribute in part to its formation. 



Tragus. The thickened margin of the anterior wall 

 of the concha, situated between the incisura 

 intertragica and the crus helicis. Regarded as a 

 part of the closure mechanism. 



Tuberculum anthelicis [His]. Auricular hillock No. 4. 



Tuberculum arterius [His]. Auricular hillock No. 2, 

 the middle hillock of the mandibular arch. 



Tuberculum auriculae. The so-called Darwin's tuber- 

 cle. Corresponds to the true ear-tip of the long- 

 eared mammals [Schwalbe]. 



Tuberculum centrale [His]. Transverse elevation in 

 floor of fossa angularis, separating it into an 

 upper and a lower depression, the lower becoming 

 the auditory meatus. It arises as a bulging of 

 the closure plate of the first gill-cleft. 



Tuberculum innominatum. Small cartilaginous antero- 

 lateral elevation at junction of horizontal portion 

 of crus helicis with the helix ascendens, i. e., 

 mandibular portion of helix. 



Tuberculum intermedius [His]. Auricular hillock 

 No. 3, the one at the top of the first branchial 

 cleft. 



Tuberculum supratragicum [His]. Term applied to the 

 accessory elevation that sometimes is found at 

 the upper edge of the tragus. In these cases the 

 tragus may be regarded as two-lobed. The 

 separation of the tragus into two lobes occurs in 

 varying degrees of distinctness. 



Tuberculum tragicum [His]. Auricular hillock No. 1, 

 the lowest, hillock of the mandibular arch, giving 

 origin to the tragus. 



