52 



Xystophords. Richardson. 



Plate XXX., fig. 22. 



We here exhibit another of Dr. Hooker's drawings 

 (No. 90), representing a small fish taken at sea. It ap- 

 pears to be a fish of the Cottoid family, and is named from 

 the armature of its head. Judging from the figure, the 

 formula for the fin-rays appears to be D. 5]24 ; A. 3|16, 

 &c., and the fish would seem to be scaleless, from the way 

 in which the muscular fibres are shown. 



OsTKACiON Boops. Richardson. 



Radii: — C. 12; A. 14; P. 14. (Dr. Hooker). 



Plate XXX., figs. 18—21. 



Being unwilling that any of the novel forms of fish 

 sketched by Dr. Hooker should be altogether lost to sci- 

 ence, though the specimens from which they were designed 

 have perished, we here present an Ostracion, in which the 

 chief novelty appears to be the want of a dorsal fin. Dr. 

 Hooker has given four views of this little fish in different 

 positions, viz., 18, a lateral view, 19, a view of the back, 

 terminated at each end by a long spine, and with tsvo 

 smaller intermediate eminences, which seem to replace the 

 dorsal fin. Fig. 20 shows the under surface, when the fish 

 is turned, so as to bring the mouth and frontal spine into 

 view ; and 21, the posterior surface, looking from the vent 

 over the anal and caudal fin to the long caudal spine. 

 The drawings are numbered 34 by Dr. Hooker. 



Hab. Taken in the South Atlantic, in a tow net. 



Syngnathus hymenolomus. Richardson. 



Ch. Spec. Syvgn. corpore valde compresso, superne iii- 

 /erneque memhrand lata marginato ; caudd quoque 

 superne antice marginatd. 



Radii :— D. 41 ; C. 8. Scutelli i— corporis 30 ; cauda; 67. 

 Plate XXX., figs. 11, 12, 13. 



Baron Cuvier, in the Regne Animal, divides the Syn- 

 gnathi into four groups, characterized by the number of fins 

 they possess. The species we have figured having merely 

 a dorsal and anal, would enter the third group, of which 

 Syngn. ccquoreus of Montagu (Trans, of the Wern. Soc. 

 i. pi. 4, fig. 1) is the type, but it has also a broad, thickish, 

 membranous border, or adipose fin, not noticed in any 

 described member of the genus, which may be considei-ed 

 as giving it a claim to be ranked as the type of a separate 

 group. It is not, however, advisable to attempt giving its 

 distinctive characters in this point of view, until the whole 

 fainily shall have been revised, for the purpose of fully 

 discriminating the various groups which it comprises, and 

 arranging the known species, now become numerous. My 

 friend Mr. Gray has made some progress in this task, which 

 coidd not be in better hands ; in the meantime, I have 

 given the fish a specific name, indicating its most sticking 

 pecidiarity, and which may be employed as a generic 



appellation hereafter, if need be. It is compiled from uix-tv, 

 membrana, and xaiMoi, margo. The British Museum pos- 

 sesses many specimens brought from the Falklands, by 

 Mr. Wright, which Mr. Gray has kindly permitted me to 

 examine, and they would appear to be all females, or at 

 least they show no traces of pits on the belly, for the re- 

 ception of the eggs, such as we observe in the male Syngn. 

 (Bquoreus, nor of a pouch under the tail, as in the gi-oups 

 which have four or five fins. 



In this Syngnalhus, the vent is a very little posterior to 

 the middle, and the body is much compressed, with flatly 

 convex sides, edged on the dorsal and ventral line by 

 broad, thickish, opake folds of skin, which double its 

 height. The shields by which the body is protected, 

 show very slightly through the integument, and are not 

 angular. The upper cutaneous border is interrupted on 

 the twenty-first shield, on the hinder part of which the 

 dorsal begins, and is continued to the thirty-third shield. 

 On the thirty-fourth shield the border again appears, but 

 not so broad, and it goes on decreasing in height to the 

 eighty-eighth, where it ends, the tail at the same time 

 growing more and more slender, and ending in a narrow 

 point, but supporting a very small caudal, with eight sim- 

 ple jointed rays. The under cutaneous border ends just 

 before the anus, around which there is a dense patch of 

 villi, which conceal the orifice, and cover a space of the 

 length of a shield and a half. 



The snout, measured to the fore part of the orbit, is 

 one twenty-fourth part of the entire length of the fish, and 

 the head, from the tip of the snout to the end of the oper- 

 culum, forms between the twelfth and thirteenth part. The 

 snout is compressed, obtuse above, and more acute below. 

 A flattish space, with a faint mesial ridge equal to a dia- 

 meter of the orbit, separates the eyes above. A smooth, 

 somewhat elevated, superciliary ridge on each side of this 

 space, and extending to the nostrils, renders it concave. 

 The opercidum is obtusely oval, and it shows little pits on 

 its surface, disposed in lines. Other parts of the head 

 and snout show similar pits as the fish dries, but in the 

 recent stale, the bones must be tolerably well covered by 

 the integuments, and there are no rough ridges, or angular 

 points, except a projection, apparently of the subopercu- 

 lum, which is joined to its fellow underneath, and points 

 directly downwards, below the short vertical limb of the 

 preoperculum. The gill-opening is very minute, and is 

 pierced over the posterior quarter of the operculum. 



All the specimens have been kept long in spirits, and 

 have a dull brownish tint, without spots. 



DIMENSIONS. 



Length from end of snout to tip of iLiil 12-05 inches. 



vent 6-15 „ 



„ „ end of gill-plale 095 „ 



„ ,, gill-opening 0'9I „ 



eye 050 „ 



Length from vent to tip of tail 5-90 „ 



Some specimens measure five or six inches more in 

 length. 



Hab. The harbours of the Falkland Islands. 



