;i78 LABYRINTBICI. 



totnl length, the length of the head thrice and two-thirds. Inter- 

 aiid subopcrciilum minntely denticulated. Greyish, with darker lines 

 along the series of scales. 

 Java, Siimatra, Borneo. 



a. Fine specimen. 



According to Dr. v. Blecker's ol)servation, the number of the dorsal 

 and anal spines appears to be subject to considerable variations. 



5. POLYACANTHUS. 



Polyacanthus, {K. 8,- v. II.) Cm: ^ Val vii. p. 353. 



Body compressed, oblong ; operculum without spines or scrrature ; 

 cleft of tlie mouth small, more or less oblique, not extending beyond 

 the vertical from the orbit, and little protractile. Small fixed teeth in 

 the jaws, none on the palate. Dorsal and anal spines numerous (13- 

 20) ; ventral fins composed of one spine and five well-developed rays ; 

 the soft dorsal and anal, the caudal and the ventral more or less elon- 

 gate in mature specimens. Caudal rounded. Lateral line interrupted 

 or absent. Branchial arches with toothed tubercles. Ak-bladder 

 simple; pseudobranchia) none (glandular). Pyloric appendages in 

 small number ; intestine "\AT.th many circumvolutions. 



Fresh waters of the East Indies. 



1. Polyacanthus hasselti. 



Polyacanthus hasselti, Cuv. .ij- VuLVxi. p. 353. pis. 195, 205; Cuv.HPffne 

 Anuii.IlLPoias. pi. 72. tig. 1; Bleck.Verhaml. Batai: Genootsch. xxiii. 

 p. 9. 



kulilii, lilcch. Topoijr. Batnv. 



B. 4. D. i^JP. A. m. L. lat. 31-32. L. transv. 7/13. 



Ca3c. pylor. 2. Vert. 11/16. 



The height of the body is nearly one-half of the total length (the 

 caudal fin not included), the length of the head two-sevenths. 

 Lateral line interrupted. Pra^orbital not serrated. The first soft ray 

 of the ventral fin is produced into two filaments of moderate length. 

 Coloration uniform. 



Java, Sumatra, Borneo. 



a. Fine specimen. 



2. Polyacanthus einthovenii. 



Bleckcr, BvDieo, v. p. 423. 



B. 6. D. 1^. A. If. L. lat. 32. 



The height of the body is contained twice and three-fourths in the 

 total length, the length of the head three times and three-fourths. 

 Lateral line interrupted. Green, Avith black vertical stripes ; a 

 round black spot on the middle of the base of the soft dorsal fin ; 

 caudal membrane dotted with black. {Bl.) 



Bivers of Sambas (West. Borneo). Sumatra, 



