1001 



its two halves ;ire joined in IVoiit (ml/), at the syiu- 

 nhysis, inereh' In' eai'tilage instead of the ordinary 

 firm sutiu'c. 



The lonii' niaxillaries (iii.r), whieh arc somewhat 

 curved and t\\'isted, are tootidess, and llie sin_L,rl(. or 

 sometimes (in front) (h)nlih' I'ow of intei'maxiiiar\' teeth 

 are not \er\- iai-ge; hut all the yreati'r is the size of 

 the teetli on tlie head (vom) of the vomer, in the inner 

 rows on tjie palatines (pi), and, above all, in the lower 



o\er wiru-li the eard of teeth (extends, being thus raised 

 fi'ce above the hind ]iart nl' tlie jjharyngcal itself. All 

 the hones already enumerated in the mouth and pha- 

 rynx may be dentigerous in most of the Teleosts; but 

 in the Pike we further lind lliat the gill-rakers, on the 

 front of tlie In'anehial ai'ehes, are transformed into dense 

 cards of teetii, di\ided into (luadrilateraj or rounded 

 (verrueose) groups, and containing teetli about equal 

 in size to the intermaxillary ones. The nund)er of the 



jaw {(h'). In the long, posteriorly pointed patch of j teeth is thus augmented so considerabh' that Khoveu 



teeth thai oecu])ies the siiaCt (romp) of the vomer, ex- 

 tending l)ack to a line witli tlie nasal cavities, the 

 dense teeth decrease in size behind, a diminution which 

 also appears, both outwards and backwards, in the some- 

 what broader card of ])alatine teeth, which extends a 

 little further back than the vomerine card. The man- 

 diliular teeth of young Pike are set throughout in one 

 roAv; ill large Pike there are tw(j rows at the extrc^me 

 front, both being incurved (recurved) nearest to the 

 syniphvsis. Iiiit only one row throughout the; rest of 

 the jaw margin. The front teeth ai'e comparative!)' 

 small, about twice as large as the intermaxillary teeth; 

 but the size increases backwards, while the teeth be- 

 come more scattered, the posterior two-thirds of the 

 jaw margin being armed with only about G large ca- 

 nines. Among these canines the middle ones are the 

 largest, being of so considerable a size that in Pike 9 

 dm. long the largest mandibular tooth measures together 

 with its base 19 mm. "and above the gum 14 mm. 

 The tongue is cartilaginous, somewhat broader in front, 

 but incised at the truncate tip. The hind part of its 

 lingual bone and the three copular bones (the first and 

 largest of which is formed by the coalescence of two), 

 are set with dense cards of small teeth. The roof of 

 the pharj'nx is armed -with t^vo pairs of cards, on the 

 upper pharj'ngeals, containing teeth about etiual in size 

 to the foremost in the lower jaw, the anterior cards 

 pointed in front, and both cards together of about tlie 

 same size and form as either of the two cards on the 

 lower jiharyngeals. The last-mentioned bones are slen- 



succceded in counting "certainly more than three tiiou- 

 sand teeth" in tlie moutii and pharynx of a j'ike. All 

 the teeth are ophidian in type, jjointed, foi- the mo.st 

 part curved, rigid in an outward direction, flexibk; to- 

 wards the interior of the mouth, with the tip directed 

 inwards and backwards, thus affording a ready ingress 

 to the prey, but preventing its egress. Exceptional in 

 form are the straight small teeth on the branchial ar- 

 ches, and the largest canines in the lower jaw, which 

 are also straight, but dagger-shaped and two-edged. 



The number of the branchiostegal rays varies be- 

 tween 13 and 16, being not unfrequently different on 

 either side. All of them are sabre-curved, the posterior 

 sharp, the anterior rather more terete. The anterior 

 (lower) 6 or 7 are set on the ceratohyoid bone, and 

 are somew'hat separated from the posterior (usually 8), 

 which belong to the epihyoid. The branchiostegal mem- 

 branes are free and sejiarate underneath to the root of 

 the tongue, where they are attached, the verj' extre- 

 mities crossing each other. This arrangement further 

 contributes to the distensibility of the pharynx. 



The top of the head is flat, with a concavity be- 

 tween the eyes. These are large", ovaP, rather far 

 apart'', and set high, about half-way along the head'. 

 Above their anterior part projects a semi-elliptical or 

 rounded quadrilateral bone (fig. 253, .s^jo) that calls to 

 mind the superciliary shield in birds of prey, and gives 

 the Pike a similar fierce and savage look. The nasal 

 cavities are large, and lie just in front of the eyes, 

 each containing two apertures, the anterior round, the 



der (resembling branchial arches), but furnished on the | posterior furnished with a rounded dermal lid, origi- 

 posterior inward side with an elevated, fiat jn-ocess, ', nating from tlie fairly broad ridge of skin between them. 



" Ttie Iciiigituilinal diameter df Uio eyes measures in Die young about ' ,, in Pilie 4 — 5 dm. long about '/g — '/s, oi the length 

 of the head. 



' The vertical diameter of the eyes is about 80 — 85 % of the longitudinal. 



' The interorbital width at the middle of the eyes is about ',', (19 — 21 %) of the length of the liead. 



'' The length of the snout is about 42 (sometimes 40) — 45 K. and the postorbital length about 43 (in the fry .37) — 46 °i, of the 

 length of the head. 



