85 



Sy/ig/ial/iiisQ) iiticinalus I )iincker, Mitt. a. d. naliirh. .Mus. Hamburg, X.WII. 

 191 5, p. 86. 



D. 28 ; P. 1 5 ; Rings 15 -f 42 ; Sub- 

 dorsal rings I + 7. 



Slender. Trunk heptagonal, the 

 ventral keels strongly prominent; 

 tail tetragonal. Shields transversely 

 striated, their edges strongly pro- 

 minent, finely but very sharply 

 serrated, terminating in a hindward 

 curved spine. Intermedial shields 

 (scutella) wanting. Superior cristae 

 of trunk terminating near end of 

 dorsal; superior cristae of tail with 

 their anterior part deflected and con- 

 tinued to last ring of trunk; where 

 they are situated above the end of 

 the median cristae of trunk. Inferior 

 cristae of trunk and tail continuous. 

 Head 8'/., times in length, twice in 

 that of trunk. Snout equal to re- 

 maining part of head, thrice longer 

 than diameter of eye; it is cylin- 

 drical but somewhat compressed ; 

 its superior profile obliquely conti- 

 nued in that of the posterior part 

 of the head. A median denticulated 

 keel begins on the posterior half 

 of the snout and is continued with 

 two intervals on the occiput and 

 nape; serrated supraorbital edges 

 commence before the nostrils and 

 terminate on occiput. Similar edges 

 laterally on snout. Operculum with 

 a complete serrated longitudinal keel 

 from which radiate pennatiform 

 edges. Tail more than 2 ',2 times as 

 long as trunk. Subdorsal rings in- 

 flated ; dorsal fin therefore somewhat elevated above level of 

 dorsal profile. Caudal rounded, much shorter than postorbital 

 part of head. Yellowish, ventral part of trunk brown as also 



l"^ig- 35- 



S\'ni;/iat/uis uncinattis M. Web. 

 X37- 



