FISHES. 15 



they are represented by mistake in figure 15 as uniserial. The vomerine and palatine teeth 

 form a continued series of short teeth with rounded cusps, the vomerine teeth being some- 

 what larger and more prominent than the palatine ones. The mandibular ones resemble the 

 latter, and stand in two rows at the end of the jaw. The first dorsal is connected to the 

 second by membrane, and the pectoral and caudal are ovate. The ventrals are furnished with 

 a spine and two unbranched jointed rays, the second soft ray being closely applied to the 

 first and so slender as to be detected with difficulty. The dorsal and anal are connected to 

 the base of the caudal by low membrane, and there are similar cutaneous folds in the axillary 

 of the ventrals. Length, 3^ inches. 

 Hab. China Sea. 



TETRODON ATRATUS, Richardson. 



Radii.— B. 5; D. 9 ; A. 8 ; C 8i-; P. 17. 



Plate VII. Fig. 1-3. 



This Tetrodon belongs to the group which have short heads, a generally hispid body, 

 and pale spots. The spines are small, scarcely protrude even on the belly through the inte- 

 gument, and are but very little pungent to the finger, as they sink beneath the skin when 

 pressed. They are most conspicuous on the belly, but become visible on the back when the 

 skin is inflated. They can be traced over all the back, nearly to the base of the dorsal, and 

 down the sides over the styloid bone, till they meet the spinous skin of the belly. Some very 

 delicate ones are detected with difficulty on the lateral line, where it traverses the trunk of 

 the tail, and a few also at the posterior part of the base of the dorsal. The top of the head is 

 also set with minute spines, but the snout anterior to the nostrils, the chin, cheeks, the 

 pectoral axillae, the flanks posterior to the point of the styloid bone, and the whole of the tail, 

 except the lateral lines, are smooth. The lateral line can be traced from near the nostril in a 

 curve, under the eye, over the shoulder and pectoral fin with some slight undulations, and 

 then straight through the tail, above the middle height. Porous lines can also be traced over 

 the eye, and one line runs from the caudal fin through the lower third of the tail. The skin 

 along this fine is minutely granulated, as if spinous, but the spines are neither visible by aid 

 of a single lens, nor sensible to the touch. The rest of the integument above and below is 

 quite smooth. 



The obtuse chin projects beyond the mouth, which is thus turned obliquely upwards. 

 The profile is slightly concave at the nostrils, and convex at the eye, from whence it runs 

 nearly horizontally to the dorsal. The belly is tumid, and is capable of considerable disten- 

 tion. The head, measured to the gill-opening, forms one-fourth of the total length of the 

 fish, caudal included ; its breadth at the gill-openings is equal to its length, and its height, 

 when the skin is flaccid, is nearly equal to its breadth. The nostrils are two small contiguous 



