DISCUSSION OF SPECIES AND THEIK DISTRIBUTION. 



19 



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

 the height of the anal; it is divided by a notch into a sliort upper portion, whose leugth is 

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

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

 caudal from the end of anal base e(pials one-fourth the length of second dorsal base. 



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

 of ])ectoral equals nearly twice tlie 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 con- 

 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 interorbital space. Tlie 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 fins were apparently faded; the original 

 color was probably grayisli brown with dark margins on all the fins except the first doisal. 

 Capello states that his example was chestnirt-brown. 



The National Museum received February 12, 1SS.'3, in the fresh state, a fine example of 

 a species of PseiMlotrincix, whicli came ashore at the Amagansett Life-Saving Station on 

 Long Island, February S, 1883, forwarded by Mr. J. 1>. Edwards, keeper of the Sufl'olk 

 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. 



MiUi- 

 meters. 



Hun 

 (Iredths 



of 

 length. 



Milli- 

 meters. 



Hun- 

 rtredths 



of 

 length. 



Total length 



Body : 



U(!i';ht at origin of first dorsal 



Hi'ight at origin of ventral 



Height at origin of second dorsal 



Height at cud of ventral base 



Least height of cauilal peduncle 



Width at origin of first dorsal 



Head: 



Distanre from tlie tip of snout to first gill 

 opening ; 



Horizontally 



obliquely ? 



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 second- . 



Height of first gill opening 



Heigiit of second gill opening 



Heiglit of third gill opening 



Height of fourth gill opening 



Height of fifth gill opening 



Height at angle of mouth 



Height at first gill opening 



Height at base of pectoral 



Distance from tip of snout to eye (horizon- 

 tally) 



Distance from tipof snout to nioutli (lioi-i- 

 zontally) 



3,950 



100.0 



Head—Con tin ued . 



Distance from tip of snout to raouth (ob- 

 liquely) 



Distancefroni tip of snout to angleof month 



(borizontally) 



Distanre from tip of snout to angle of luoutb 



(obliquely) , 



Distance from tip of snout to spirarlo {hor- 

 izontally) , 



Greatest leugth of f^piraclo 



Length of opeuing of spiracle 



Distance from cj'c to spiracle 



Distance from angU^ of mouth to spiracle . . 



Leogtb of orbit 



Leugth of eye 



AVidth of mouth 



Length of upper jaw to angle of mouth... 

 Length of lower jaw to angle of mouth . . , 



Distance from mouth to nostril 



Distance bet ween nostrils 



Distance between eyes 



Distance between eyes on cartilage 



Distance betweeu spiracles 



First dorsal : 



Distance from suout 



Length of base 



Greatest height 



Second dorsal : 



Distance from eud of first dorsal 



Distance from snout 



Length of base - 



147 



280 



5.0 

 9.5 



