50 

 Key to the indo-australian species of Doryichthys. 



I. Inferior cristae of trunk and tail discontinuous. 

 A. Dorsal with more than 50 rays; situated above 



an equal number of rings of trunk and tail . . D. splnachloldcs p. 50. 

 /?. Dorsal with less than 50 rays; the subdorsal 



tail-rings are more numerous than the subdorsal 



trunk-rings. 



1. Tail shorter than trunk and head. Snout longer 

 than postorbital part of head. Dorsal with 



42 rays , D. caiidocarlnatus p. 51. 



2. Tail longer than trunk and head. Snout equal 

 to or somewhat shorter than postorbital part 

 of head. 



a. Dorsal with 24 rays . D. brcvidorsalis p. 51. 



b. Dorsal with 34 40 rays D. rctzil p. 52. 



II. Inferior cristae of trunk and tail continuous. 



I. Length of snout much more than remaining part 



of head, equal to twice the postorbital space . . D. deokhatoldes p. 53. 

 i 2. Length of snout equal to or less than remaining 



part of head D. martensi p. 54. 



Doubtful species . D. jluviatilis p. 55. 



i. Doryichthys spinachioides Dunck. 



Doryichthys spinachioidcs Duncker, Mitt. a. d. naturh. Mus. Hamburg XXXII. 

 1915, P- 52. 



D. 66 ; A. 4 ; P. 19 ; C. 9 ; Rings 16 -f- 27 ; subdorsal rings 6 + 6, 

 Edges of body smooth, those of head finely serrated. Snout 

 robust, somewhat shorter than postorbital part of head. Inferior 

 cristae of trunk and tail discontinuous, median cristae of trunk 

 and inferior cristae of tail continuous. Operculum with com- 

 plete, finely serrated longitudinal keel and fine, smooth radiating 

 ridges below it, the uppermost of them is the most prominent 

 and nearly parallel to the principal keel. Anal before the 

 middle of the length ; the caudal, which is of medium size, 

 included. The nuchal crista reaches to the first dorsal inter- 

 medial shield; the other intermedial shields (scutella) without 

 keel. Grey above, silvery white below; trunk laterally with a 

 diffuse dark band; operculum silvery. Length of the single 

 specimen known, a female, 82 mm. [After DUNCKER, not 

 seen by us]. 



Habitat: North New Guinea (Kaiserin Augusta river). 



