51 317 



and longest less strong; all are simple, unbianched, evenly tapering and pointed; 

 viewed under a microscope Iheir distal part appears longitudinally divided, but the 

 two halves are tightly adpressed; no joints (or only a few and indistinct traces) 

 are to be seen"^^'. 



The cranial skeleton, hi general appearance the head resembles that of 

 a Syngnathid. In proportion to the brain-case the snout part is extremely prolonged 

 and strongly compressed laterally. As in Syngnathids the quadrato-mandihular 

 articulation is situated almost below the front end of the vomer, thus the position 

 of the mandible when the mouth is closed is almost vertical (opposite to the case 

 in Fistularia, Aulostoma and Centriscus, but agreeing with Aniphisile, Siphonostoma 

 etc.). On the upper side of the skull ',> crests are observed, one median, shorter, 

 on the supraoccipital, and 2 lateral, longer, beginning at the hind margin of the 

 epiotics, running forwards on the frontals, rising in height over the orbits and 

 from here converging towards the mesethmoid, where they merge into one sharp 

 edge just above the anterior ends of the nasal fossæ. The crests are (or may be) 

 finely denticulated (especially in S. paradoxus). 



The supraoccipital joins the trontals; parietals (and opislhotics) are 

 absent. 



The epiotic is large; just below the posterior end of the crest mentioned above 

 an ossified tendon for the strong nuchal muscles is fastened (cfr. p. 815 [49]), and 

 below this bone the epiotic is connected with the upper fork of the posttemporal 

 (pt). The exoccipital carries a lateral process for connection with the articular 

 process of the first vertebra; both exoccipitals meet above the occipital foramen. 

 The articular face of the basioccipital is concave, oblique in position, sloping from 

 behind forwards and downwards. On the lower face of the skull the basioccipital 

 is laterally expanded (above the parasphenoid) and in front separated from the 

 prootic by a narrow cartilage (as in Siingiiatluis). The plerotic (sq) is large, reach- 

 ing the basioccipital below and thus intervening between the exoccipital and the 

 prootic Posteriorly the pterotic carries a crest, connected with the lower fork of 

 the posttemporal; in front it forms together with the prootic the posterior articular 

 face for the hyomandihular, while the anterior articular face belongs to the prootic 

 and poslfrontal. 



The greater part of the cranial "beak" belongs to the mesethmoid. This 

 bone embraces most of the nasal fossa, forming the greater part of its roof and 

 floor and its whole median wall, while the rest of the fossa is bounded by the 

 frontal and prefrontal. Just in front of the nasal fossa the mesethmoid carries a 

 strong lateral spine, which may be more or less branched, and seems most strongly 

 developed in S. paradoxus. 



The vomer (vo) is short in proportion to the mesethmoid, laterally compres- 

 sed towards its front end. As in Syngnathus a small rounded rostral cartilage is 

 [)resent. The posterior end of the vomer underlies only the foremost part of the 

 mesethmoid, reaching behind about to Ihe level of the oblique suture between the 



41* 



