DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 



19 



The caudal originates at a distance from the end of the second dorsal about equal to 



the height of the anal; it is divided by a notch into a short upper portion, whose length* is 

 very little more than the greatest height of first dorsal, and a very low and long lower por 

 tion, the longest margin of which is nearly twice as long as the snout. The distance of the 

 caudal from the end of anal base equals one-fourth the length of second dorsal base. 



The distance of pectoral from snout is contained five times in total length; the length 

 of pectoral equals nearly twice the width of its base, and is a little more than one-ninth of 

 total length. The greatest width of pectoral equals twice the height of anal, and is eon 

 tained twelve and one third times in total length. 



The origin of the ventral is slightly in advance of the end of first dorsal, and is behind 

 the middle of total length a distance equal to the interoibital space. The length of ventral 

 equals that of lower jaw. The width of ventral base equals that of pectoral base; the great- 

 est width of ventral slightly exceeds its length. 



Color. — When received the margins of the tins were apparently faded: the original 

 color was probably grayish brown with dark margins on all the fins except the first dorsal. 

 Gapello states that his example was chestnut-brown. 



The National Museum received February 12, 1883, in the fresh state, a fine example of 

 a species of Pseurlotriiiris, which came ashore at the Amaganseft Life-Saving Station on 

 Long Island, February 8, l.ss:3, forwarded by Mr. J. 15. Edwards, keeper of the Suffolk 

 Life-Saving station. [The specimen is the one here described.] 



No species of the genus Pseudotriacis has heretofore been recorded in the western At- 

 lantic. 



The gills and mouth were obstructed by sand. The only parasites discovered on the 

 animal were a couple of isopods, one of which was found in the eye cavity. 



MEASUREMENTS. 



Total length 



Body : 



Height at origin of first dorsal 



Hi i^lit at origin of ventral 



Height at origin of second dorsal 



Height at end of ventral base 



Least height of caudal peduncle 



Width at origin of first dorsal 



Head: 



Distance from the tip of snout to first gill 

 opening: 



Horizontally 



OliliqiH 1\ 



Distance from tip of snout to last gill open- 

 ing 



Distance from first gill opening to fifth 



Distance from first gill opening to fourth .. 



Distance from first gill opening to third. . . . 



Distance from first gill opening to sec 1.. 



Height of first gill opening 



Seight of second gill opening 



Height of third gill opening 



Height of fourth gill opening 



Height of lifth gill opening 



Height at angle of mouth 



Height at first ^ill opening 



Height at base of pectoral 



Distance from tip of snout to eye (horizon- 

 tally) 



Distance from" tip of snout to month i hori- 

 zontally) 



2,950 



Head —Continued. 



Distance f rom tip of snout to mouth (ob- 

 liquely) 



Distance from tip of snout to angleof mouth 



(horizontally) 



Distance from tip of snout to angle of mouth 



(obliquely) 



Distance from tip of snout to spiracle (hoi 



izontally) 



1 rreatest length of spiracle 



Length of opening of spiracle 



Distance from eye to spiracle 



Distance fnun angle of mouth to spiracle 



Length of orbit 



Lengt li of eye 



Width of month 



Length oi upper ja^ to angle of month.. 

 Length of lower jaw to angle of mouth. . 



Distance from mouth to nostril 



Distance between uostrils 



Distance between eyes 



Distance bet ween eyes on cartilage 



Distance between spiracles 



First dorsal: 



Distance from snout 



Length of base 



( treat is t height 



s. cond dorsal : 



Distance from end of first ilorsal 



Distance from bhouJ 



Length of base 



305 



5.0 



9.5 



10.3 



