334 68 



lamellæ leave the gill-arches and take their origin from the pharyngeal wall; 

 further in the shape of the pectoral pterygials, and in the weakening of the anterior 

 border of the scapular foramen; if the weak or cartilaginous anterior part of the 

 scapula atrophied, we should have the condition found in Solenostomus, from which 

 a step farther leads to that of Syngnathidce. The large ossified nuchal tendons, so 

 characteristic of the Aulostomidœ , also occur in Solenostomidœ and at least in one 

 of the Synynathidœ , namely Neruphis ophidian. The genus Fistularia, besides, has 

 the symplectic connected with the ethmoid region of the skull as in the Lopho- 

 branchii, and with the Syngnathidœ it shares the loss of the first dorsal fin, which 

 in Aulostoma is so to speak going to disappear. In both Aiilostoma and Fistularia 

 the outer ray of the ventral fin has given up its spinous character, perhaps a step 

 towards degradation of the fin; the separation of the pelvic bones in the median 

 line and the weak structure of these bones might possibly point in the same 

 direction. 



In spite of the many features of far going specialisation the family Centriscidœ 

 must be considered to contain upon the whole the least aberrant members of the 

 suborder Solenichthyes; to this conclusion point the facts, that all the components 

 of the mandibular suspensory parts are present, that nasals are well developed, 

 that the branchial skeleton is complete, the shape of the pectoral pterygials, the 

 structure of the ventral fins etc. 



Notes. 



Aulostoma. 



1 p. 270 [4]. The scales are regarded by most authors as simply ctenoid. A figure is 

 found in Kner (28 b, p. 259 [28]); the scale represented shows seven teeth, united Ijasalty into 

 one part, which appears separated Ijy a distinct boundary line from the main scale-plate; that 

 this representation is incorrect can easily l)e verified. 



2 p. 271 [5]. Tlie very conspicuous system of "inscriptiones tendineæ" is — as far as I 

 know — only mentioned in recent times, by A. S. Woodwakd (59, p. 375), in his definition of 

 the genus Aulostoma: "Intermuscular bones very numerous and long". But already Agassiz 

 wtio, curiously enough, does not appear to have known tlieir existence in the living forms, 

 states for the fossil A. bolcense (1, T. 4, p. 282): "I)e nombreuses arêtes musculaires effilées parais- 

 sent avoir soutenu les muscles tout le long de la colonne vertébrale", and fig. 3 of his PI. 35 

 stiows tliese structures very distinctly. 



3 p. 274 [8]. Bridge (5, p. 576) has correctly described the interspinous bones for the un- 

 paired fins in Aulostoma chinense; Ijut he does not mention the anterior ray-less elements of 

 the anterior part of the trunk, in front of the spinous section of the dorsal fin. 



