;{:);{ 77 



res»:ir(linf> Fixtiilnria. On p. 575 S W. writes: ". . . all are alike in the absence ol' an opistliotic* 

 and basis])henoi(l, the even upper surface, the sculpturing; of the roolinf^ bones, the simplicity 

 of the post-temporal, the essential shape of the ethmoid and the great size of the 

 supra-occipital, which separates the parietals widely, and appears to separate 

 the hinder portion of the frontals. In (iasterosteus the exoccipital extends forwards between 

 tlie i)tcrotics and basioccipital to tlie ])ro-otic. In the others the pterotic extends ventrally 

 to the basioccipital, and also part of the way into the larj^e meml)ranous space be- 

 tween this and the pro-otic, thus separating the exoccipital widely and the basiocci- 

 pital partially, from the pro-otic .... In the sphenoidal region of Fistularia the pro-otic 

 completely encloses the foramen for the exit of part of the fifth nerve, and forms the hinder 

 boundary of the other exit. The large alisphenoid forms the front boundary of the rest. 

 No eye-muscle canal is present, consequently the parasphenoid lies Hat against the lloor of 

 the cranium. Laterally it sends out processes up to the sp h eno tic i^ postfrontal; 

 in Fist, the process is united to the prootic and does not at all reach the postfrontal)." 

 P. 570: in the anterior portion of the cranium, Fistularia and Syngnathus present the same 

 features as those given above for Gasterosteus, but it is greatly elongated, and almost com- 

 ])lelely ossified. In the first this region is proportionally much wider, because the narrow 

 pre-ethmoid is sujiplemen ted laterally by the nasals." "In the visceral skeleton 

 all are alike in the tendency towards weakening of the branchial ajiparatus", in the great 

 forward slant of the hyomandibular"", in the great elongation of the synii)lectic, in the 

 great reduction or comijlete suppression of the metap terygoid cartilage"", in 

 the absence of an ectopterygoid"*", and in the possession of the acrartete condition"! 

 "In Fistularia the reduction of the branchial skeleton has advanced much further than in 

 Syngnathus, for all the basib ran chi als and the fourth epibranchial are absent. The 

 pharyngobranchials of the second to fourth arches are present, but, unlike those of Gastero- 

 steus, the first two are fused; the tiiird is free, and all are rod-like, and lie one 

 behind the other' 1'. 577: "In the hyoid arch the basihyal (= glossohyal) though present 

 during dcvelojjmenl , is ajjsent in the adult Syngnathus ft, but attains a great lengtii in 

 Fistularia." "Of the bones immediately concerned in the gill-cover and branchiostegal mem- 

 brane, the operculum alone survives in Syngnathus ftt, but are all present, together with five 

 l)ranchiostegaI rays, in the Fistularia," P. 578: "In Fistularia the inner lamina of the 

 suborbital bone alone remains, the quadrate is much larger ])osteriorly, and the ptery- 

 goid bone bears a close resemblance to that of Gasterosteus. Between the hinder process 

 of the last named bone and the suborbital is the undoubted metapterygoid, which thus 

 occupies a similar position to, but is much smaller than, a in Sy ngnat h us." fftf 

 What SwiNNERTON here calls the suborbital must be the sym|)lcctic in Fistularia; of sub- 



' In Gasterosteus an opisthotic is present ! 



•" In Gasterosteus I cannot admit any "weakening" of this apparatus. 



*■■ In Gasterosteus, Spinacliia, etc. the hyomandibular is not more sloping forwards tlian in 

 very man3' other fishes (nor in Syngnatlius]. 



"" In Gasterosteus, Spinacliia, Eucalia , Apeltcs etc. an ossified metapterygoid is present (over- 

 looked by SwiNNEKTON In his monograph!); in Syngnatlius only (as in the other Lophobranchiates) it 

 is absent. 



..... -j-jjg ectopterygoid is present in Syngnathus (and Lophobranchiates general!}')- 



f The acrartete condition is defined by Swinnertox as the condition, in which the attachment 

 of the palatine cartilage or its derivatives is confined solely to the preethmoid cornua. Now, in Fist. 

 the palatine is attached to the vomer alone. 



ff It is present in all adult Syngnathids. 



fff In Syngnatlius and all the Lophobranchiates all ii opercular bones are present, and 1 or 2 

 branchiostegals. 



ffff a in Syngnathus is the anterior infraorbital bone; comp, the reproduction of Swinneutox's 

 figure .')0, p. 356 [90| with my fig. i on PI. V, and what is said on p. 356 [90] of this paper. 



