302 KAMAKICHI KßHISODYE : 



of the body (fig. 35). The head Ls saa:ewhat biangiilarly pjTamidal, as its 

 upioer surface is more or less flat and the lateral sides obliqne, meeting at tl:e 

 veuti-al median line. This characteiistic form is very well developed in the 

 Plecostei, while it is rather a little modified in the Cybiida?, as the head is 

 more compressed laterally tliau in other families, and its top is more or less 

 vaulted. 



lu the Scombridse the suout is modertitely long, ca. 1/3 the length of 

 head, and the posterior nostrils are slit-like. In the Cv^büdfe the snout is 

 ii^.uch elongated, being neai'ly eijual iu length \\ith the pdvt lieliind the eye. 

 The anterior and ^»sterior nosti-ils are neai'er to each other, than iu the 

 Rcombridse and Plecostei, and the jws'erior nostrils are more or less elliptical 

 and a httle lai'ger than the anterior. In the Plecostei the suout Ls ca. 1/3 the 

 length of the head, but it seems rather short, as the head is broad. In the 

 genus Aims the suout is xevj short, being only ca. 1/4 the length of the 

 head. The Japanese name for the fishes of that genus is " mtdüia," which 

 n:eans that the e^e is near tlie suout. The antiior nostiils iU'o quite small, 

 <nnd the posterior nostrils ai'e mere slits. 



The mouth is tenuiual, not protractile. In the Scombrids.e it is rather 

 wide, the liind end of the upjxr jaw reaching or jMssing l»yond the vertical 

 fiom the middle of the eye ; and the mai'gin of the upjjer jaw is mostly" 

 fbrmcd by the preorbital. Tlie supplementary Ixine to the lui^xillar^- is verj- 

 nan■o^\• and small iu this family. Iu the Cybiida^ the mouth is v«y wide, the 

 iwsterior end of the upjxjr jaw generali}' re.U'hiug lieyoud thi> iX)sterior margiu 

 of the eye. But iu Acantlioq/lium, Grammatarcymis, and Gi/nmosarda the 

 maxillary scarcely rea«'h the vertical from the center of the eye. Iu Acmdhocybhuu 

 the preorbital ftirms the p)sttrior part of the ui5\x:-r jaw. The supplementai'y 

 bone to | the maxillary has its psttrior end romided. Tu the Plecostei tlK> 

 miiuth is comparatively small, the posteric>r end of the upper jaw not reachiug 

 the vertical from the middle of the eye. Tlie supx^lementarv Iwno to the 

 maxillary has a bruad straight side at the posterior cud. Aji ()bli(pu'l,\- 

 downward gi'ove iu the skiu fiom the gaiK> of the mouth is deep and 

 conspicuous. 



Iu the so-called scombroid fi-shes the teeth in the jjiws are aiTanged iu 

 one row onlj-. Thej- arj a little more numerous iu the ni>i;er thau in the 



