COMMON SEA-CAT. 



233 



of growth undergone by these p;irts of tlie body, run 

 in opposite directions. IJound the eye there is a ring 

 of tine, white pores or dermal openings of the system 

 of tlie lateral line. Similar pores also occur, in the 

 usual manner, along the lower jaw and on the sides 

 of the head, which are covered Avith a tliick skin, en- 

 tirely enveloping the bones of the gill-cover. The 

 nostrils are set about half-way between the snout and 

 the eye, one on each side, and are raised into cy- 

 lindrical dermal tubes. The mouth is middle-sized and 

 furnished with fleshy lips, which form thick folds, 

 especially at the corners. In consequence of the iirm, 

 cartilaginous connexion between the strong, but shoi't, 

 intermaxillary bones and the front part of the skull 

 (the point of the ethmoid bone), the upper jaw admits 

 of only slight motion, and the opening and closing of 

 the mouth are performed almost entirely by the lower 

 jaw. On each side of the intermaxillary bones we find 

 two or three strong, conical teeth, widened and grooved 

 at the base, like the tusks of the predatory mammals, 

 but blunt at the top, set one in front of another, and 

 each fastened to a hard osseous socket. Within these 

 teeth is a row of 5 or 6 (in old specimens generally 

 fewer) smaller, somewhat compressed, shorter teeth. 

 On the palate are three double rows of thick, globular 

 teeth, with raised, osseous bases. In the middle row, 

 whicli contains the largest teeth, and is set on the 

 vomer, there are generally four ])airs of teeth with an 

 even, worn surface, the penultimate pair being con- 

 siderably larger than the others. In each of the lateral 

 palatine rows there are two roM's, each containing four 

 oi- five blunt teeth, those of the one row alternating 

 with the other; and these roAvs are attached to the 

 two ])alatine bones. In the front of the lower jaw there 

 are from 4 to 6 tusk-like teeth in a. row, and within 

 this roAv begin tlie two longitudinal rows of shorter, 

 globular jaAv-teeth, molars with flat, worn crown and sur- 

 face sloping inwards. Of these molars the middle ones 

 are the largest. In the roof of the throat there are 

 three upper pharyngeals on each side, united together 

 into a roundish bone, and furnished with scattered, 

 cardiforra, conical and curved teeth; and beneath these 

 two longer lower j^haryngeal bones with similar teeth, 

 forming an angle in front. The tongue is fleshy, but 

 short, somewhat pointed and toothless. The four branch- 

 ial arches are furnished in front with spines covered 

 with skin. The gill-openings are of moderate size and 

 almost vertical. The branchiostegal membranes are 



Scatulinavia?i Fishes. 



furnished Avitli 7 rays and inferioi'ly united to the isth- 

 mus, just below the insertion of the pectoral fins. 



The body is covered with a thick and tough skin, 

 which at first sight seems to be scaleless and protected 

 only by an abundant, mucous secretion; but on closer 

 examination we find small, round, thin scales, deeply 

 imbedded in the skin and scattered, not contiguous. 

 The latei-al line is hardly visible, being most distinct 

 in the anterior part of the body, where the dermal 

 pores wliicli belong to it, are genei'ally clearly marked 

 I)y their white colour. The line runs almost straight 

 along tlie middle of the body. The vent is large, some- 

 what pendent and situated a little in front of the 

 middle of the body. 



The dorsal fin begins somewhat in front of the 

 perpendicular from the insertion of the pectoral fins, 

 the distance between it and the tip ,of the snout being 

 alwa)\s somewhat less than the length of the head, and 

 runs with fairly uniform height along the back very 

 close to the caudal fin, where it ends in an obliquely 

 truncate and rounded corner. All the rays are simple 

 and unarticulated, but only the last 10 — 13 are really 

 hard, all the others being soft and flexible at the tip. 

 The Avhole fin is united b}' a thick and slimy mem- 

 brane. The anal fin is of the same shape as the dorsal 

 fin, but scarcely half as high, and ends in a pointed 

 corner vertically below the end of the latter. The first 

 ray is unarticulated, but soft; all the other I'ays are 

 articulated, the anterior ones being simple, the posterior 

 branched at the tip. The pectoral fins are large and 

 rounded; when expanded, they are almost circular. 

 Their branched, thick, weak and fleshj' rays give them 

 a striate appearance, which reminds us of the shell of 

 the scallop (Pecten). Their length in proportion to that 

 of the body diminishes Avith age, varj-ing from about 

 16 to slightly more than 13 % thereof. The ventral 

 fins are Avanting. The caudal fin is small, with rounded 

 tip and 20 or 21 rays, only 13, hoAvever, being branched, 

 and only the 11 middle ones extending to the true 

 hind margin of the fin. 



We have not remarked any considerable difterence 

 betAveen the sexes. 



The colour is a uniform dark gray. The sides 

 are marked Avith more or less distinct, black transA'erse 

 belts, Avliicli varA' in number and shape, and are gener- 

 ally composed of a number of confluent, small spots. 

 The belts are continued, though more indistinctly, on 

 tlie dorsal fin. The colour of the eye is very dark, 



30 



