392 ' SCOMBRID^. 



its distance from the caudal is more than one-half the length of the 

 head. The caudal is forked, of moderate length. The anal com- 

 mences before the vertical from the origin of the soft dorsal, and 

 terminates opposite to the end of the latter. The spines are stout, 

 but short ; the fin is low, and can be received in a scaly sheath. 

 The pectoral is situated somewhat above the middle of the body, 

 slightly pointed, rather short, one-sixth of the total length, and 

 reaching to the vertical from the vent. The ventral is composed of 

 a spine of moderate size, and five rays, inserted behind the vertical 

 from the root of the pectoral, very short, one-eleventh of the total 

 length, and not extending to the vent. 



The scales are of moderate size, and higher than long ; the lateral 

 striae run parallel to the edge, and the free portion is covered with 

 excessively small prickles, the margin being minutely serrated ; the 

 posterior portion has neither striae nor folds. 

 The colour is now uniform silveiy. 



inches, lines. 



Total length 7 11 



Height of the body 2 



Length of the head 1 6 



Diameter of the eye 4 



Length of the pectoral 1 1 



of the ventral 7 



15. DITREMA. 



Ditrema, Schleg. Faun. Jcupon. Poiss. p. 77. , 



The body is compressed and oblong, covered with smooth scales 

 of moderate size ; cleft of the mouth moderately wide, armed in both 

 the jaws with a single series of small teeth ; no teeth on the palate. 

 A single dorsal, with a distinct spinous portion, formed by ten spines, 

 the posterior of which are the longest ; anal mth three spines ; 

 ventrals thoracic, composed of one spine and five rays. A second 

 opening behind the vent. 



Sea of Japan. 



1. Ditrema laeve. 



Ditrema, Schley. I. c. pi. 40. f. 2. 



(?B. 6.) D.i^. A.^. V. 1/5. L.lat. 76. 



Coloration uniform ; the spinoiis dorsal edged with black. The 

 ventrals are inserted somewhat behind the pectorals. 

 Sea of Japan. 



rt. Nine inches long : stuiied. 



