The Amphibian Jarynx. 



29'; 



I. Mandibular f 

 arch i 



II. Hyoid 

 arch 



III. 1st branchial 



arch 



IV. 2nd branchial f 



arch I 



Dorso-mandibularis 

 Pharyngo-mandibularis 



Dorso-hyoideus 

 Pharyngo-hyoideus 



Dorso-branchialis , 



Masseter, Temporalis etc, 

 Intermaxillaris anterior. 



Digastricus (of Amphibia). 

 Intermaxillaris posterior. 



= Levator arcus I. (fails in 

 = Fails ' ). [Necturiis). 



= Levator arcus II. 

 = Fails 1). 



= Levator arcus III. 



= Portion of "Hyo-trachealis" 

 or "Hyo-pharyngeus" that 

 inserts on the 3'"'' epi- 

 branchial. 



= Levator arcus IV. 

 arch i Pharyngo-branchialis^ = Remainder of "Hyo-trache- 



alis" s. "Hyo-pharyngeus". 



V. 3rd branchial 

 arch 



Pharyngo-branchialis , 



Dorso-branchialis g 

 Pharyngo-branchialis ^ 



Dorso -bran chialis g 

 Pharyngo-branchialis ^ 



VI.2)4t'i branchialf Dorso-branchialis j 



With regard to the muscles of the 1^^ visceral arch {b^^ branchial) 

 there is ground for controversy. Although the Dorso-branchialis.^ 

 is plainly represented by the „Dorso- tr ache alls", has Necturus 

 any equivalent for the 5'^ Pharyngo-branchialV For this place 

 I may suggest the muscles lying upon the larynx itself (Fig. 24), re- 

 ferred to by GöPPERT as the Laryngei. According to this author, 

 these muscles are in their origin merely portions of the general pha- 

 ryngeal sheet lying about the larynx which have become secondarily 

 connected with the laryngeal cartilages. The portion which lies on 

 the dorsal side of the cartilages, and called by him Laryngeus 

 ■dorsalis, he derives from the Dorso-pharyngeus (i. e. Dorso- 



1) GöppERT considers that the ventral segments primarily stretched 

 from arch to arch, and thus belong to the same series as the K e r a t o - 

 hyoidei and Constrictor arcuum branchiarum. He thus 

 considers the formation of median raphes as secondary. If on the 

 other hand we assume this latter condition as primitive, the muscles 

 referred to may be considered either remnants of a deeper system 

 formerly extended interbranchially, or as modified members of the 

 system presented here. In this latter case they may represent the 

 missing 3«"d and 4t'i ventral segments. 



2) The two muscles connected with this arch 

 close relationship by the failure of the arch itself, 

 thus a digastric muscle separated by an inscription, 

 suggests the term "Digastricus pharyngis" 

 when in this mutual relationship. 



are thrown into 

 the two forming 

 GöPPERT (No. 6) 

 for the muscles 



