DISCUSSION OF SPECIES AND THEIB DISTRD3UTION. L95 



THYESITOPS VIOLACEUS, Bean. (Figure209.) 

 Thyrsitaps violaccus, Bean, Proo. 17. S. Nat. Mus., 1887, pp. 513, 514. 



A Thyrsitops with the body stout, itsgreatest width being exactly one-halfof the height 

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

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

 fourth of the standard length ; its greatest width is contained ££ times in its length. The 

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

 tained nearly 7 A times in the length oft he head and :>\ times in the length of the upper jaw. 

 The least height of the tail equals the width of t He interorbital area. The length of the 

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

 tip of the snout to the origin of the spinous dorsal. The maxilla extends to the vertical 

 through the front of the eye. The length of theupperjaw equals 3J times the width of 

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

 the eye: its length, including the fleshy tip, is 5 times the width of the interorbital area. 

 The anterior nostril is smaller than the posterior; it is situated in advanceof 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. Three large fangs 

 anteriorly in the roof of the month; pseudobranchiae well developed; no trace of gill-rakers. 

 Thespinous dorsal begins at a distance from the snout which equals twice the length of 

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

 than the third spme 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 2J 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 in front of the anal equals 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 interorbital width. The fifth ray is about two-thirds as long as the first. The pec- 

 toral begins under the second dorsal spine; its length equals 2i times the width of the 

 interorbital area. It extends to the vertical midway between the fifth 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. The scales are irregu- 

 lar in shape, thin, elongate, cycloid, and deciduous. 



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



Radial formula: D. XX, I, 19+2 Unlets; A. 17+3 finlets; V. I, 5; P. 13. 



TABLE OF MEASUREMENTS. 



Millimeters. Millimeters. 



Length to base of caudal (44 inches) 1,115 



Greatest height of body 138 



Height at ventrals 126 



Height at anal origin 11-' 



Least height of tau 40 



Greatest width of body 56 



Length of twentieth dorsal spine 25 



Length of fifth dorsal ray 78 



Length of last dorsal ray 20 



Length of second dorsal Unlet 28 



Caudal, length of middle rays - r >s 



Caudal, length of external rays 116 



Length of head 280 ' Pectoral, from tip of snout 255 



Greatest width of head 62 Length of pectoral 100 



Will th of interorbital area 40 Ventral, from tip of snout 285 



Length of snout 117 Length of first \ entral ray 30 



Length of upper .jaw 130 Length of fifth ventral ray 22 



Length of mandible, with tip 203 Vent, from dagger-shaped spine 32 



Length of mandibular tip 2:; Length of dagger-shaped spine 20 



Length of eye '■'•' Anal, from vent 45 



spinous dorsal, from tip of snout 2.'!:'. Length of fifth anal ray 72 



Length of third dorsal spine 55 Length of last anal ray 20 



Length of ninth dorsal spine 5s Length of last anal I Inlet 28 



Length of thirteenth dorsal spin.- :.s 



The type (Cat. No., I". S. X. M., 39287) was received by the National Museum from .Mr. 

 w. a. Wilcox, agent ofthe U. s. Fish Commission at Gloucester, Mass., and was caught by 

 Gapt. Thomas Thompson, schooner .1/. .1. Huston, on Le Have Hank, in 125 fathoms. 



