History of the Sternoptixinae, a family of the osseous fishes, and their anatomical peculiarities : with a description of the Sternoptix celebes, a species not hitherto noticed / by P.D. Handyside.

Date:
[1839?]
Catalogue details

Licence: Public Domain Mark

Credit: History of the Sternoptixinae, a family of the osseous fishes, and their anatomical peculiarities : with a description of the Sternoptix celebes, a species not hitherto noticed / by P.D. Handyside. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    by long ribs, and, including the head and chest, is semicircular in form in front; and, while its general form is remarkably oblique, and more or less ellii^tical, it is a little elongated backwards to the point where its forked tail (which is about one-fourth of its length) begins. The lack rises into a sharp ridge, which, at its middle, supports a single fin; be- hind this fin there is a small gibbosity or hump (membranous In the spe- cies of Hermann, and Olfers, muscular in that homCelebes), in a situation corresponding to the adipose and rudimental fin of the Salmonidse, while, in front of the dorsal fin, the carinated fore part of the back after be- coming sulcated, ends in two sharp ridges, which converge towards the upper part of the head, at the interparietal bone, and thence running downwards, finally diverge towards the nares at the middle of the upper lip.* The trunk presents inferiorly, between the extremities of the hu- merals and the crests of the pelvic bones, a sharp pellucid ridge or crest, a formation which depends upon the acute junction of the extremities of the ribs. On each side of this carinated ridge there is a row of from eight to twelve small depressed surfaces, corresponding, for the most part, to the extremities of the intercostal spaces, but which, having been regarded as folds of the textures around the sternum (a bone merely as- sumed to exist), suggested the name of Sternoptix. The anus is mean (i.e. equally placed between the head and tail). The caudal region is slightly convex, and terminates by an acute carinatc edge, running along one-third of the length of the body. The outline of the head is, ante- riorly, remarkably obtuse, and the height of that region is double its length. The eyes are large, salient, and naked ; they occupy the middle third of the height of the head, and advance within a line of its anterior boundary. The mouth, which is directed upwards suddenly, descends very obliquely, so as to appear abnipt when viewed in front, and is there- fore singularly capacious in the vertical direction; and the maxillary bones (the upper of which slides over the lower) form the superficial boundary of this opening. The tongue is small and rudimental. Maxil- lary teeth exist in the Sternoptix: these are very numerous and minute. They difier, however, in the several species, both in their form and ar- rangement, appearing either en velours (as in the S. Hermanni) or en cro- chets (as in the S. Olfersii and S. Celebes). The Branchiostegous Membrane is patent, though posteriorly its mar- gin is retracted under the opercula, and in each of the semicircular inter- spaces of the branchial rays it exhibits a longitudinal depression or slial- low sinus. The Branchial Rays are from five to nine in number, very slender, naked ;it the extremity, and they curve downwards, backwards, and inwards. Opercules. The opercule is subarcuated, soft, fine, and clastic, and terminates inferiorly in a right angle, the anterior margin of which is pa- rallel to the last branchial ray, and partly covers it. The two branchial * See Pinto I. flg 2.