26 



do not appear to have been thick. The teeth are short, 

 and densely villifonu in rather broad bands on the jaws, 

 vomer, and palate bones, without canines. 



The under jaw shows a small pore on each side of the 

 symphysis, and three larger ones on each limb. This bone, 

 the jaws, the preorbitar, the very narrow suborbitar chain, 

 and the top of the head, are scaleless. The oblong pre- 

 orbitar is rounded anteriorly, and has a wide shallow curve 

 on its lower edge, which is regularly serrated. The cheek 

 is densely scaly forwards to the maxillary, having thirteen 

 rows of scales between the eye and the curve of the pre- 

 operculum, and there is a cluster of small scales behind 

 the eye, adjoining the naiTow suborbitar chain. The disk 

 of the preoperculum is bounded towards the cheek by a 

 smooth narrow ridge, or line, but is clothed by some 

 minute scales, and its outer edge is serrated. The teeth of 

 the upper limb are small and regular, while those at the 

 slightly rounded corner, and on the under limb, ai-e large, 

 inclined forwards, and divided into three or four groups. 

 Tlie scales on the gill-cover are larger than those on the 

 cheek, and hide the union of the operculum and suboper- 

 culum. The spinous point of the operculum is flat and 

 acute, and does not reach beyond the membranous edging 

 of the gill-cover. The bone is sloped away above it by an 

 oblique shallow notch, which ends in a smaller spinous 

 point, situated further forward than the under one. There 

 is a notch at the meeting of the interoperculum and sub- 

 operculum. The scaly supra-scapular space is bounded 

 by a smooth line, the scapula is toothed on the edge, and 

 the octangular disk of the coracoid bone above the pec- 

 toral is scaly, and its edge toothed. The gill-membrane 

 is partially scaly. 



The scales are reticulated on the exterior border, and 

 finely ciliated, but they feel only slightly rough when the 

 finger is drawn forwards over them. Fifty-two scales, dis- 

 tinguished by a small tube on each, compose the lateral 

 line, as far as the base of the caudal, but smaller scales 

 extend half way up that fin. 



The strong dorsal and anal spines are alternately right 

 and left. The third anal spine is rather longer, but scarcely 

 so stout as the second. The last soft rays of both fins are 

 divided to the base, the fins move in scaly grooves, and are 

 also clothed with scales for some way up. The base of 

 the pectoral is also scaly. The ventrals end in filamentous 

 tips, and have an elongated scale in the axilla. 



The smaller specimen is figured of the natural size on 

 the plate, and has the following 



DIMENSIONS. 



Length from tip of snout to base of caudal fin 8'50 inches. 



„ „ anus 5-50 „ 



Greatest height of body 330 „ 



The larger specimen is fourteen inches long, has a more 

 abruptly notched preorbitar, a proportionally longer face, 

 stronger dorsal and anal spines, and a ray fewer in the 

 pectoral, but does not seem to be specifically distinct. 



Hab. Western Australia. 



Djagramma poi 



Richardson. 



Ch. Spec. D. parte piniKe dorsi spinosd humili ; pinna 

 aiii longd ; roslro maxllldque inferior i porosis. 



Radii:— B. 7; D. 9(20; A.3|15; C. 15| ; P. 1|20; V. 1|5. 



Plate XVI., figs. 5, 6, natural size. 



This fish differs from the typical Diagrammte in several 

 respects, and especially in the lowness of the spinous part 

 of the dorsal, which, when contrasted with the higher, 

 even, soft rays, almost gives it a claim to be ranked among 

 the Scisenoids, with two dorsals. The rays of the anal are 

 twice as numerous as those of any species of Diagramina 

 mentioned in the Histoire des Poissons. Some of the 

 PristipomcB approach it in this respect, but in that genus 

 there are no scales on the dorsal or anal. 



Form compressed, the greatest height, which is at the 

 ventrals, being nearly thrice the thickness. The profile, 

 exclusive of the trunk of the tail, is luiequally ovate, the 

 head forming the obtuse end, and the belly being consider- 

 ably less arched than the back. The head makes one- 

 third of the total length, caudal excluded. The eye is 

 rather large, and is placed high up, but yet a little removed 

 from the profile, one diameter of the orbit distant from the 

 end of the snout, and two fi-om the tip of the gill-cover. 

 The mouth has a moderately large vertical gape, but is 

 cleft only a short way backwards. The teeth are very 

 small, setaceous, of irregular height, widely set, and in a 

 single row, without canines. There is a narrow velum 

 above and below, which, with the whole inside of the 

 mouth, are studded with glandular points, looking like rows 

 of teeth, but there are, in fact, no teeth on the vomer, or 

 palate. The integuments on the roof of the mouth show a 

 deep narrow mesial furrow, boimded on each side by an acute 

 membranous ridge, on the outside of which there is a shal- 

 lower groove. These parts are fringed with glands. The 

 pharyngeal teeth are villiform, and somewhat acerose. The 

 outer rakers are slender and setaceous, the others narrow 

 crests, all of them rough. The preorbitar has a straight, 

 inferior, serrated edge, which covers a little of the maxil- 

 lary. The much rounded preoperculum, and the inter- 

 operculum and suboperculum, both of which are convex 

 on the edge, are also serrated. The operculum has two 

 minute, thin, obtuse points, with an oblique angular notch 

 between, all of which are concealed by the scales. The 

 gill-cover is triangular, with a somewhat obtuse tip. The 

 gill-opening is large, and the membrane is supported by 

 seven strongish rays. The cheek, interoperculum, gill- 

 cover and supra-scapulars, are densely covered with small 

 scales ; the disk of the preoperculum, ]5reorbitar, lower jaw 

 and rest of the head, including the lines which surround 

 the supra-scapular patches, are covered with porous inte- 

 gument. The two small pores on each side of the sym- 

 physis, and the two larger ones on the limb of the lower 

 jaw, which characterise the genus, cannot be distinguished 

 from the rest. There is no pit under the chin, as in Pris- 

 tipoma. 



The ventrals, pectorals, and commencement of the dor- 

 sal, are in the same vertical line. The fourth dorsal spine 

 is the tallest, and the penultiuiate one is much shorter than 



