200 PEOF. W. K. PAJiKEE ON THE STEUCTUEE AND 



seen, confluent now with the trabuculse, but still distinct from the nasal roof, whose 

 curve they follow. 



The general direction of the suspensorium is outwards and forwards, forming an 

 angle of 45° with the axis of the skull ; it is a bilobate cartilage, with a small, square, 

 bony centre in its distal part, close above the saddle-shaped condyle {q, q.c). The angle 

 behind is rounded ; it is the otic process {ot. p), which is wedged in between the 

 tegminal edge of the auditory capsule and the squamosal. 



The inner angle or proximal part ascends as a broad tongue of cartilage, which is 

 confluent with the alisphenoid cartilage ; this is the ascending process («. p). It has a 

 thick lobe underneath it, at a short distance from the trabecula ; this is the pedicle, 

 proper (/pd), which is not confluent with the basis cranii; the part to which it articu- 

 lated is an evident " basipterygoid " lobe. In the middle of the fore edge of the 

 suspensorium a papilla of cartilage is seen in front of the " sphenotic horn ;" this is the 

 first appearance of the pterygoid cartilage [pg. c). This skull is now at a stage com- 

 parable to that of the adult Frofeits, Menohranclms, and Siren. This cartilage, which 

 appears here just before metamorphosis, is chondrifled in the Frog simultaneously with 

 the trabecula and the suspensorium. 



c. Free Arches of a larger Larva q/" Triton cristatus, 2 inches 11 lines long. 



These arches are from the largest larva of this species ever obtained by me ; and it is 

 well worthy of remark that in the next to be described, which was fast becoming 

 cryjitohrancltiate, and which represents the permanent form of Sieboldia and Meno- 

 jpoma, the length was -^ of an inch less than this, the ripest form of the larva, as such. 



Afterwards the creature grows again ; but the metamorphosis is attended constantly, 

 I believe, by at least a temporary diminution in the size of the animal. 



The mandible of the larval Newt has for its axis a strong, arched, articulate Meckelian 

 rod (fig. 5, ar. c, mJe), which has a cylindroidal condyle, and then lessens gradually to 

 its rounded end near the chin ; it has a large dentary [d) and a small splenial {spl) 

 investing it ; and the articulare {ar) is now a large trough. 



The epihyal is suppressed ; the ceratohyal {c.hy) is very similar to Meckel's cartilage 

 but Is flatter, and its upper end is an elongated tongue and not a condyle. There is no 

 separate basihyal segment ; but the first basibranchial pushes between the cornua, which 

 show no hypohyal segment. 



The first and second branchial arches (fig. 5) have each a ceratobranchial segment, 

 [c.hr), half as long and half as wide as the epibranchial {e.br). These distal parts are 

 like slender phalanges ; the proximal segments are fiat and falciform. 



The series of four epibranchials {e.hr^'^) decrease in size backwards, each articulating 

 with the hinder angle of the one before it ; the first joins on to the two ceratobran- 

 chials, the second to the first epibranchial and its own ceratobranchial ; and the two 

 last have only the epibranchial attachments. The last carries no gills ; the interspaces 



