188 



CALIFORNIA ACADEMY OF SCIENCES 



The last two or three rays in the dorsal and anal fins are progressively shortened, giving a 

 rounded contour to the end of these fins. The last rays of each are united for their whole length by 

 membrane to the caudal. In three specimens at hand the second dorsal contains respectively 30, 31, 

 and 32 rays; the anal 29, 29, and 30. 



Two pairs of filaments project from the free margin behind the upper lip, one in front of each 

 eye, the second pair nearer the median line. A pair of similar filaments on lower lip near symphysis. 

 No other filaments on head or body; but pairs of inconspicuous thick fleshy lobes close in front of the 

 isolated sensory organs on the lower jaw, and on the sides and top of the head. 



The opercular spine, and the spines of the dorsal fin are wholly enveloped in the integument. 

 They contain a central canal, which ojiens in a shallow groove on the anterior face of the spine, at an 

 appreciable distance below the tip. 



The genus Dcector Jordan & Everraaun (1898, pp. 2313 and 2325), of which 

 this species is the type, seems to have little value, and is not here recognized. The 

 characters assigned are the many rayed dorsal and anal fins, and the union of these 

 with the caudal. Other species of Thalaa&oiylir yne have 19, 20, and 26 rays in the 

 dorsal fin; 18, 19, and 25 rays in the anal. It seems unwarrantable to distinguish 

 from these generically a species containing 30 to 33 rays in the dorsal and 29 or 30 

 in the anal. As regards union of the dorsal and anal fins with the caudal, this occurs 

 in varying degrees, and is not correlated with increased number of fin rays. 

 T. maculosa (D. II, 19; A. 18) seems to have the fins wholly distinct; T. amazonica 

 (D. II, 20; A. 18) has them completely joined; T. reticulata (D. II, 26; A. 25) has 

 them almost wholly united. 



Measurements in Hundredths of Length without Caudal. 



Length to base of caudal in mm 



Length of head 



Greatest width of head 



Length of snout 



Diameter of eyeball 



Interorbital width 



Length of maxillary 



Greatest depth of body 



Depth of caudal peduncle 



.Snout to first dorsal spine 



Base of second dorsal (to base of last ray) 



Snout to front of anal 



Base of anal (to base of last ray) 



Length of caudal 



Length of pectoral (from middle of axil).. 

 Length of outer ventral ray 



134 



272 



23i 



.1 1 



42 

 2 



6 



13 



20 



25 

 61 



39 

 58 

 16 

 18 

 9 



