120 



(laik parts in the plate have a deep brown hue in the spe- 

 cimen, which has been long in spirits ; and the inside of 

 the mouth is of a bright reddish-orange, which also tinges, 

 though not so deeply, the corner of the mouth and the 

 parts which are exposed by the protraction of the inter- 

 maxillaries. 



Length of the specimen 13j inches. 



Hab. Norfolk Island. 



Crenidens simplex. Richardson. 

 Radii :— B. 6 ? D. 15|12 ; A. 3ll2 ; C. 15| ; P. 16 ; V. 1|5. 



Only one member of this genus is described in the His- 

 toire des Poissons, namely, the Crenidens forskaUi, which 

 has the cutting edge of each tooth divided by notches into 

 five even cusps. Several other members of the group in- 

 habit the seas of China and Australia. One of these, C. 

 punctata (Richardson, Rep. of Br. Assoc, for 1845, p. 242 ; 

 Girelln pitnciata, Gray, 111. Ind. Zool., PI. 98, figs. 3, 4) 

 has tricuspid teeth, as has also C. triglyphus (page 36 of 

 the present work, and Plate XXV., fig. 2) and C.melanich- 

 thyn (Temm. et Schl. Faun. Jap. p. 75, PI. 39; Rep. Br. 

 Assoc, p. 243). The teeth of C. tephrteops of King 

 George's Sound, described above in page 69, and figured 

 on Plate XLL, fig. 1, are also tricuspid ; but the cusps, 

 instead of being equal as in the preceding species, have 

 tlie middle one considerably wider and longer than the 

 side ones. C. zebra (p. 70 mipra) and C. leoniniis are 

 described from drawings, and the forms of their teeth are 

 unknown to me ; but one species which, like triffli/phtis, 

 is an inhabitant of Port Jackson, has all the external cha- 

 racters of the genus, except that the teeth are entire, and 

 not in accordance therefore with the scientific appellation 

 of the group. The following description was drawn up 

 iiom a dried specimen, numbered 46, 10, 22, 11, in the 

 British Museum. 



The general form is not very dissiiTiilar to that of C. 

 forskalU or trif/lyphus, but the profile of the forehead is 

 more sloping. The height of the body is contained thrice 

 and one-third in the total length of the fish. The head 

 forms a fifth part of the whole length. The diameter of 

 the eye is equal to a quarter of the length of the head. 

 Two small round nostrils are placed immediately before 

 the eye on each side. The maxillary is slender, and lies 

 in a deep furrow behind the premaxillaries, being hidden 

 when they are retracted : the dilated end is visible behind 

 the corner of the month, and glides under the edge of the 

 preorbitar. The premaxillaries and lower jaw are armed 

 with many rows of teeth, which have narrow bases, and 

 dilate gradually towards their truncated, entire, cutting 

 edges. The four outer rows on the edges of the jaws are 

 slightly incurved, and in consequence of their position are 

 separated by a gap from a dense cluster of much smaller, 

 but otherwise similar teeth, covering the more interior sur- 

 face of the jaws. In the recent fish these inner teeth, ow- 

 ing to their tips only being visible, may be mistaken for 



granular teeth, but they have the same form with the larger 

 outer ones, and are evidently destined to replace them 

 when they are worn down, in the same manner that the in- 

 ner teeth of a shark roll outwards on the edge of the jaw 

 as they are needed. The four outer rows are obliquely 

 tiled, the innermost of them being the highest. A circular 

 plate on the vomer is rough with minute teeth, invisible to 

 the naked eye ; and there is a smaller plate of the same 

 kind on the fore end of each palate bone, which is sepa- 

 rated from the vomerine plate by a narrow interval. The 

 tongue is porous, the isthmus smooth ; the under pharyn- 

 geals are armed by short, subulate, recurved, densely 

 crowded teeth. The branchial arches are each furnished 

 by two rows of thin crests placed transversely, and bristly 

 with minute hair-like teeth. Jaws, snout, preorbitar, nar- 

 row snborbitar chain, temples, disk of preoperculum, inter- 

 operculum, suboperculum and lower half of operculum, 

 with the scapular, scaleless. Seven rows of scales cover 

 the cheek between the curve of the preoperculum and the 

 orbit, and there are about as many on the upper half of the 

 operculum. Bony operculum widely notched ; the upper 

 corner of the notch greatly rounded oft', the lower part of 

 the curve much more sudden, and terminated by an acute 

 corner, which is passed by the narrow tip of the suboper- 

 culum. The notch is filled in the recent fish by smooth 

 membrane. The scales of the body have the same oblong 

 form with those of the other species described in this work. 

 A meniscoid segment of the exposed disk of each scale is 

 traversed by rough radiating lines, which end in minute 

 marginal teeth. The middle of the disk is smooth and 

 shining, and more posteriorly the lines of structure are lon- 

 gitudinal and parallel. Fifty-five scales complete the 

 lateral line, and there are about ten rows of scales above 

 it, and twenty below, where the height of the body is 

 greatest. The scales are smallest on the nape, breast and 

 belly, and largest on the sides below the lateral line, and 

 on the tail generally. A fillet of small scales runs along 

 the base of the dorsal, and another along the anal. Small 

 scales also cover the base of the caudal, and there are mi- 

 nute scales on the membranes of the solt dorsal and anal, 

 with narrow tapeiing fillets running up behind the alternate 

 sjjines, as in the triglyphus. Lateral line considerably 

 above the middle of the height, following the curve of the 

 back, and unbroken. Ventral spine slender, one-third 

 shorter than the soft rays, and standing under the third dor- 

 sal spine and attachment of the lowest pectoral ray. In 

 triglyphus and tephrxops the ventral spine is under the be- 

 ginning of the dorsal. Dorsal spines rather slender, very 

 acute, and about equal in height to the soft rays. Anal 

 spines stouter, the third scarcely taller than the second, 

 and about one-third longer than the first one, which stands 

 under the last dorsal spine. Soft part of the fin higher 

 than the dorsal and much rounded. Caudal moderately 

 concave at the end. 



Length of specimen 12 inches. 



Hab. Port Jackson. 



