OCR Text |
Show 1894.] PROE. R. COLLETT ON A NEW AGONOID PISH. 671 Thus in four specimens of different sizes the proportions are the following :- Total length 183 millim Head-length 3-66 times. Total length 254 millim „ 3-73 „ Total length 277 millim „ 4-01 „ Total length 290 millim „ 4-02 „ Snout very long, 3 times longer (or more) than the interorbital space (between the bases of the supraocular spines). Posterior part of the head comparatively smooth, the interorbital space rather concave; no quadrangular pit on the occiput in front of the dorsal scales. Eye comparatively large ; the horizontal diameter a little larger than the vertical. It is contained a little more than 2 times in the length of the snout, and rather more than 4 times in the length of head. Cirri on lower side of snout (in front of the premaxillary) and at the angles of the jaws 1. Their length equals that of the eye. Mouth entirely inferior ; distance from premaxillaries to tip of rostral spines about equal to the length of the eye. Teeth in the jaws; vomerine or palatine teeth none. Armature of the head.-Much like that of A. acipenserinus. The rostral spines 4, two projecting horizontally forwards, two (behind the first) curved backwards. A third pair on the snout (much nearer the eye than the rostral spines). Orbital ridge with a single spine (supraocular, no preocular); the lower ridge finely serrated. Occipital ridges, operculum, and preoperculum as in A. acipenserinus, but the spines more pointed and longer. Suborbital with a double ridge at its lower margin, the upper ridge with two distinct spines behind, and a third (sometimes indistinct) at equal distance from the eye and the tip of the snout. Head with about 18 distinct spines altogether. Armature of body.-Plates on the back and sides of the same number as in A. acipenserinus, but the spines are longer and curved more backwards, and strong everyAvhere from head to caudal. Between the two dorsal keels and between the two lateral keels there are no traces of another keel (as in A. valsus). Breast with about 10 polygonal plates, 4 of which form a series on each side and 2 a median series ; bases of pectorals and ventrals also surrounded with plates. All the plates have a short spine in their centre. Dorsal plates numbering:- Plates. From occiput to first dorsal (Pair) 4 First dorsal extending over „ 8 Between the dorsals „ 3 are1 lAolstl. tFSherec osompne dcs iedmcoeonrnssd aa lrde oe irxnst aae lnb datdio n sgcta aotuevd eoafrl p reservation( aSnidn„ gm loes)t of1 t95h e + b a1r bels |