T 
516 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 
SYNOPSISAND DESCRIPTIONS OF THE AMERICAN RHINOBATID#. 
By SAMUEL GARMAN. 
RHINOBATID A. 
Trunk broad, flat; tail long, strong, continuous with the body; dor- 
sals and caudal well developed; pectorals not reaching the end of the 
snout (except species of Discobatidae); covered with shagreen; with 
spines in a vertebral row and on the shoulders; generally viviparous. 
RHINOBATUS. 
Nasal valves not extended upon the space between the nostrils ; 
two flolds on the spiracle; rostral cartilage 
medium, the ridges a 
separate ; 
snout pointed Avis 8S. 6s. oJ aciote BS leucorhynchus 
confluent half their length ; 
snout rounded on. the end. ....-.. ..68 -- 424.02 s-- --.-productus 
produced, narrow; groove short, small; ridges 
confluent more than half their length. -.......... . +... Spinosus 
long; ridges straight, confluent 
less than half their length ; 
four patches of spines on the shoulders ; 
COLOTMOMMTOLM) ee .as- aici ssiente- ajtiaise op sie aha ste aisles . horkelit 
more than half their length ; 
two patches of spines on shoulders ; 
clouded"or BIlOtGhed. 22h. < 225 sujac ae ee ae eee undulatus 
close together, narrowly separated at the base; 
rarely with spines on the shoulders ; 
freekiéd swith whitish 2... 2 fe 2 ateheate lentiginosus 
one fold on the spiracle; snout blunt, rounded ; 
Head iH abee occ sare ce sate oeiee Dias Oy tae eee ers ....-planiceps 
SYRRHINA. 
Nasal valves extended on the internarial space ; 
a fold on the hinder margin of the spiracle; 
rostral ridges meeting’). e:\22 50)... Ss eh brevirostris 
no fold on the spiracle ; 
rostral ridges not meeting ..6-.... 2262.6. Rivonia Reno et exasperata 
PLATYRHINOIDIS. 
Labial fold distinct ; 
no fold on the spiracle; 
posterior lobe of nasal valve rudimentary ..... wd ncaa tae ET CSET DUEL 
