DISCUSSION OP SPECIES AND THEIR DISTRIBUTION. 195 



THYRSITOPS VIOLACEUS, Bean. (Figure 2UU.) 

 Thyrgitopa violaccus, Bean, Proc. U. S. Nat. Mus., 1887, pp. 513, 514. 



A ThijrsUops with the body stout, its greatest width being ex;i<;tly one-half of the height 

 at the anal origin. The greatest height of the body is one-half of the length of the head, 

 and is contained 8 times in the total length without caudal. The length of the head is one- 

 fourth of the standard length; its greatest width is coutained 4i times in its length. Tlie 

 widthof the interorbital area is slightly greater than the length of the eye, which is con- 

 tained nearly T.J times in the length of th(3 liead and 3.^ times in the length of the upper jaw. 

 The least height of the tail eiiuals the width of the iuterorbital area. The length of the 

 snout equals twice the length of longest dorsal spine, and one-half the distance from the 

 tip of the snout to the origin of the spinous dorsal. The maxilla ext(Mids to the vertical 

 througli the front of the eye. The length of the upper jaw equals 3^ times the width of 

 the interorbital space. The mandible reaches to the vertical through the hind uuirgiu of 

 the eye; its leugth, including the tleshy tip, is 5 times the width of the iuterorbital area. 

 The anterior nostril is smaller than the posterior; it is situated in advance of the eye one 

 diameter of the eye. The posterior nostril is a narrow slit placed midway between the ante- 

 rior and the eye. Strong teeth on the intermaxillary and mandible. Tluee large fangs 

 anteriorly in tlie roof of the mouth ; pseudobrauchi;e well developed; no trace of gill-rakers. 

 The spinous dorsal begins at a distance from the snout which equals twice the leugth of 

 the snout; it is highest iu the middle. The ninth and thirteenth spines are slightly longer 

 than tiie third spine and more than twice as long as the twentieth, their length equaling 

 one-half that of the snout. The soft dorsal is highest anteriorly, its longest ray, the fifth, 

 being nearly twice the least height of the tail. The caudal is forked; its middle rays about 

 one-half as long as the external rays. The anal origin is under the third ray of the soft 

 dorsal, its distance from the vent 2^ times the length of the dagger-shaped spine. The vent 

 is directly under the end of the spinous dorsal. The anal rays are longest anteriorly, the 

 fifth ray being nearly as long as the corresponding ray of the soft dorsal. The dagger- 

 shaped spine iu front of the anal e(iuals one-half the least height of the tail. The ventral 

 is immediately under the third spine of dorsal; its first and longest ray equals three-fourths 

 of the iuterorbital width. The fifth ray is about two-thii'ds as long as the first. The pec- 

 toral begins under the second dorsal spine; its length e(iuals 2i times the widthof the 

 interorbital area. It extends to the vertical midway between the lifth and six dorsal spines. 



The lateral line is well developed ; it descends gradually from the upper angle of the gill 

 opening, reaching the median line of the body under the soft dorsal. Tlie scales are irregu- 

 lar in .shape, thin, elongate, cycloid, an<l decitluoiis. 



Color, purplish. The spinous dorsal, pectorals, ventrals, aud inside of mouth blackish. 



Eadial formula: I), xx, i, 19-1-2 fiulets; A. 17+3 fiulets; Y. i, o; 1*. 13. 



TABLE OF MEASUREiMENTS. 



Millimeters. itillinn-ters. 



Leugth to base of caud.il (44 inches) 1,115 



Greatest height of bodv 138 



Height at ventrals 126 



Height at anal origin 112 



Least height of tail 40 



Greatest width of body 56 



Length of head '. 280 



Greatest width of head 62 



Width of interorbital area 40 



Lengtli of snout 117 



Length of upper j aw 1 30 



Length of mandible, with tip 203 



Length of twentieth dors.al 8)Mne 25 



Lengtli of fiftli dorsal ray 78 



Length of last dorsal ray 20 



Length of second dorsal finlet 28 



Caudal, length of middle rays 58 



Caudal, length of external rays 116 



Pectoral, from tip of snout 2.55 



Length of pectoral 100 



Ventral, I'rom tip of snout 285 



Lengtli of lirst ventral ray 30 



Length of tifth ventral ray 22 



Vent, from dagger-shapiMl s]iiuc .32 



Length of m.andibular tip 23 i Length of dagger-shaped spine 20 



Length of eye 37 



Spinous dorsal, from tip of snout 233 



Length of third dorsal 8]>ino 55 



Anal, from vent i-i 



Length of fi Ith anal ray 72 



Length of last anal ray 20 



Length of ninth dorsal spine 58 ! Length of last anal Unlet 28 



Length of thirteenth dorsal siniv; 58 



The type (Cat. No., F. S. N". M., 30287) was received by the National :Mu.seum from Mr. 

 W. A. Wilcox, agent of the TJ. S. Pish Commissiim at Gloucester, :\Iass., and was caught by 

 Capt. Thomas Thompson, schooner ^1/. A. Baston, on Lc Have Bank, in 12.5 fathoms. 



