but beliiiid (witliin) this vnw lie two or tiirfc rou-.s of 

 coinpensatory teeth, directed iinviu'ds atid downwards. 

 Thick dermal folds form, as usual, transverse curtains 

 and cover the inner rows of teeth both in the upper 

 jaw and the lower. The tongue is broad and flat. (_)n 

 opening the mouth, we can see from within straight 

 through the large spiracles, which here, as in the pre- 

 ceding species, have the anterior margin double. Here 

 too thej' lie obliciuely behind and above (within) the 

 posterior ends of the orliits, so far iinvards that the 

 distance betw-een them is only about ■*/,, of the inter- 

 orbital width, and so far back that their distance from 

 the tij) of the snout measures somewhat more than 7s 

 of the length of the head. Their width is about half 

 the external diameter of the iris. The gill-openings 

 are still smaller than in the Picked Dog-fish. They 

 are scarcely larger than the spiracles, or even smaller 

 than these. The last three are often set so close to- 

 gether that at a casual glance one may fail to distin- 

 guish between them, this being the probable explana- 

 tion of Rafinesque's above-mentioned mistake. 



All the fins are extremely thin at the outer mar- 

 gin, without scaly covering, and more or less trans- 

 parent. They are consequently torn in most cases at 

 tlie said margin, and they are seldom seen so entire as 

 in our figure, which is drawn from a newh' caught 

 specimen in a good state of preservation. 



The dorsal tins are distinguished by the posterior 

 being considerably larger than the anterior and having 

 about twice as large a spine. The first dorsal fin com- 

 mences at the end of the first third of the body, the 

 second somewhat before the end of the second third 

 thereof. The form of the first dorsal calls to mind 

 that of the adipose fin in the Sal monoids, the second 

 is raoi-e typically a Shark fin, with concave outer pos- 

 terior margin. The caudal fin, as a whole, is sickle- 

 shaped, with the usual sinuses in the under margin 

 only subindicated. The laterally compressed tip of the 

 tail forms a slight upward curve within it. From the 

 beginning of the upper lobe the caudal fin measures 

 rather more than '5, from that of the lower lobe rather 

 less than ^,4, of the entire length of the bodj'. 



The insertion of the obtusely rounded pectoral fins 

 commences at a distance from the tip of the snout 

 measuring somewhat more than '/j of the length of the 

 bodv. Their length is about 8 — 8\\, % of that of the 



!E. 11 fj.') 



l)od\- or 43 — b4 % of that (jf the head; and the l)readtii 

 of their base is ahout 52 — 56 % of their length. The 

 ventral fins are elongated, with the outer angle strongly 

 rounded. Their insertion, which measures about 8'/j 

 — iJ'Vj ">' of the length of the bod)% begins at a distance 

 from the tip of tlie snout answering to about 54 — 56 % 

 of the said length. The pterygopodia of the fully ma- 

 ture males — figured by DOmerii,, 1. c, PI. 4, fig. 13 — 

 have before the tip three curved and pointed spines, two 

 of which — the (jutermost being molnle — are set at 

 the outer margin of the cleft on the upper side of these 

 organs, the third being hidden in the skin near the top 

 of the inner tegumentary margin of the cleft. The 

 cloacal aperture occupies about the postei'ior half of 

 the space between the ventral fins. 



The scaly armature we have already noticed. The 

 lateral line is sometimes cjuite distinct, marked by a 

 black punctuation, and follo\ving a rather straight course, 

 near the back, until it comes within the region of the 

 caudal fin, where it o-ooks downwards to follow the 

 inferior margin of the tip of the tail and pass straight 

 out over the fin itself. 



The coloration is distinguished from that of the 

 preceding Sharks first and foremost by its being darkest 

 on the ventral side; and from this black colour a stripe 

 ascends on each side behind the ventral fins and ex- 

 pands both forwards, above the said fins, and backwards 

 on the sides of the tail. Another similar stripe runs 

 up before the beginning of the inferior caudal lobe and 

 spreads along the lower pai-t of the tip of i he tail. The 

 termination of the lateral line is also marked by a fine, 

 coal-black streak along the under margin of the tip of 

 the tail. The l)lackisli blue colour of the back and 

 sides acquires along the middle of the latter a more 

 or less distinct silvery band, due to the gi-ajdsh lustre 

 of the setiform scales. The iris has a greenish metallic 

 lustre: the pupU is green. The dorsal fin-spines and 

 the teeth, as well as the outer parts of the eyes, are 

 conspicuously marked by their white colour. 



The Sagre is strictly a deep-sea fish, and it con- 

 sequently- shares with several other fishes" the pecu- 

 liarity of having been found in widely separated loca- 

 lities without being discovered in the interjacent regions. 

 Thus it was first described by Willughby from the 

 Mediterranean, where it was already known — more 

 than three hundred vears ago — to the Genoese fisher- 



for example above, p. 155, on the Blue-mouth 



