90 Edwin Cbapin Starks, 



There is no process sent backward from tlie metapterygoid across 

 the inner surface of the hyomandibular. There is no space left 

 between the articular and dentary. The maxillary bears a small 

 auxiliary maxillary as in Scomber. The short premaxillary proc- 

 esses project into the concavity in the front of the ethmoid. The 

 teeth in the dentary and premaxillaries are large and laterally flat- 

 tened ; the vomer and palatine bear small granular teeth. 



The third and fourth superior pharyngeals are not nearly so closely 

 attached to form a single plate as in Scomber, and the teeth on both 

 the superior and inferior pharyngeals are smaller, stiffer, and less 

 brush-like. The hypercoracoid foramen is large and through the 

 center of the bone. The pelvic girdle is more slender and the vertical 

 plate is but little developed. 



The vertebrae number 19 abdominal, 29 caudal, or a total of 49 

 with the hypural. The condition of the parapophyses, zygopophyses, 

 ribs, epipleurals, and interspinous bones is similar to those of 

 Scomber. The haemal and neural processes are more slender, fragile, 

 and fibrous than in any other genus of the Scombridse. The caudal 

 rays lap over the hypural plate even farther than in Scomber, or until 

 the bases of the opposite rays meet on the median line and hide the 

 plate almost completely. The urostyle of the hypural is better 

 developed. 



Aside from these characters Scomberomorus is as described for 

 Scomber. 



ACANTHOCYBIUM. 



A heart of Acaiitlioc-yhiniii solaiirtri. Cuvier anrt Valeiifiennes, iuchidiiig: the 

 upper elements of the shoulrter girdle and the first three vertebrie, from the 

 Hawaiian Islands. 



In this genus the cranial crests extend straight forward as in 

 Scomberomorus, not obliquely towards the suborbital margin as in the 

 Thunninte and Sardinae; there is no auxiliary crest as in Scomber- 

 omorus. Both the temporal and supraoccipital crests stop, however, 

 at the front of the eye, and the top of the cranium anterior to them 

 is evenly rounded transversely unlike any other genus of its family. 

 The supraoccipital covers the exoccipital suture rather broadly as in 

 Scomberomorus. The preorbital part of the cranium is noticeably 



