318 52 



quadrate and Ihe synipleclic, ending lar in front of the parasphenoid. The anterior 

 end of the parasphenoid is found at a level with the middle of the nasal fossa. 

 Thus a large part of the lower face of the mesethmoid intervenes between the 

 vomer and parasphenoid forming alone the roof of the mouth-tube as in Fistularia 

 and Aiilostoma; this part of the mesethmoid is excavated below, with projecting 

 margins, to which the suspensory bones (entopterygoid and mainly the symplectic 

 (sy)) are fastened. The parasphenoid forms an obtuse angle below the posterior 

 margin of the orbit and reaches along the proolics and basioccipital almost to the 

 articular condyle of the latter. At the posterior orbital wall the parasphenoid 

 sends out an ascending process to meet the front pari of tlie prootic and the ali- 

 sphenoid. Between this process and its fellow from the opposite side the upper 

 face is somewhat hollowed for the attachment of the inferior musculi recti of the 

 eye. As far as 1 could make out no bridging over of this muscular fossa by the 

 prootics or alisphenoids is found, and consequently no "myodoma" is developed. 

 The alisphenoid is fairly large, forming part of the orbital wall between the frontal, 

 postfrontal, prootic and ascending process of the parasphenoid. 



The intermaxilla (i) has a distinct but small ascending part connected with 

 the rostral cartilage; the maxilla (mx) is relatively large, as usual connected 

 with the vomer and rostral cartilage and with the maxillary process of the palatine. 

 The lower jaw (PI. VI, fig. 6) seems only to be composed of the articular (ar) and 

 the (edentulous) dental (d); a separate angular 1 have not been able to make out. 



The hyomandibular (PI. VII, fig. 3 by) is short, comparatively slender; its outer 

 face joining the preoperculum is sculptured, its inner face anteriorly drawn out 

 into a slight ala; its lower end is cartilaginous and joins the hind end of the 

 horizontal symplectic (sy). The latter forms a long and high plate, the upper 

 margin of which joins the mesethmoid, the lower margin is thickened and con- 

 tains a cartilaginous axis; the bifurcation characteristic for the Syngnathids is ab- 

 sent here. Anteriorly it joins the quadrate in a long oblique suture, and its upper 

 anterior point overlaps suturally the posterior end of the entopterygoid (ept). As in 

 Syngnathids the metapterygoid is wanting. The entopterygoid is a narrow lamella, 

 joining the ectopterygoid (ect) anteriorly in a short suture. The latter is sabre- 

 shaped, joining the anterior thickened margin of the quadrate in a long suture, 

 and in a short suture connecting with the palatine (pa); this bone is short and 

 stout, giving otT as usual a short, diverging maxillary process. The quadrate (qu) 

 is long and high, its anterior margin almost vertical (thus in position intermediate 

 between that in Fistularia and Aulostoma on the one side and Syngnathids on the 

 other); the upper margin in front touches the entopterygoid, but apart from this 

 a narrow membranous strip intervenes between these bones as a feeble indication 

 of the large interspace found in Syngnathus; the outer face is very slightly convex 

 with a longitudinal (denticulated) crest running towards the articular head for the 

 mandible and continuing a similar crest along the preoperculum. 



The ascending part of the preoperculum (pro) is short, slightly oblique, its 



