250 



BMBIOTOOIDiE. 



Ennichthys megalops, Gii'ard, I. c. 1855, p. 323, and U. S. Pacif. R.R. 

 Exp. X. Fish. p. 197. pi. 37, pi. 26. fig. 10. 



Forehead much depressed. The height, taken from the upper axil 

 of the pectoral, equals the distance of the chin from the lower axil o\ 

 the pectoral. The middle dorsal spines are longer than the posterior. 

 Lower jaw longer than the upper; the cleft of the mouth extends 

 upwards to, or even beyond, the horizontal from the upper margin of 

 the pupil. Lips thin ; the fold of the lower continuous round the 

 jaw. Ventral black posteriorly. 



Coasts of California. 



"We are indebted to Mr. Gill for the principal characters contained 

 in the above diagnosis. 



13. Ditrema agassizii 



Hyperprosopon agassizii, Gill, in litt. 



D. |. A. ^. L. lat. 65. L. transv. 8/20. 



Eye large, longer than the snout, its length being somewhat less 

 than one- third of that of the head. Occipital region scarcely con- 

 cave. The middle dorsal spines are longer than the posterior and 

 than the soft rays. Scales on the cheek in four series. The height 

 of the body is contained twice and a seventh in the total length 

 (without caudal). The lower jaw rather longer than the upper ; the 

 maxillary extends to the vertical from the anterior margin of the 

 eye. Lips thin ; the fold of the lower continuous round the jaw. 

 Caudal fin black posteriorly ; ventral uniform whitish. 



a. Fine specimen. San Francisco. From the Boston Museum, as 

 Hyperprosopon argenteum. 



14. Ditrema auale. 



Hyperprosopon analis, Agass. 

 Hypocritichthys analis, Gill, in litt. 



D. |. A. |. L. lat. 65. L. transv. 6/10. 



Eye a little longer than the snout, its length being nearly one-fifth 

 of that of the head. The middle dorsal spines are longer than the 

 posterior. The height of the body is one-third of the total length 

 (with the caudal) ; lower jaw rather longer than the upper ; the 

 fold of the lower lip is continuous round the jaw. Top of the spinous 

 dorsal black ; a black spot in the middle of the caudal. {Gill.) 



California. 



15. Ditrema rhodoterum. 



Holconotus rhodoterus, Agass. Am. Jotirn. 1854, p. 368, and Proc. 



Post. Soc. Nat. Hist. 1861, p. 132. 

 Cymatogaster larkinsii, Gibbons, P-oc. Ac. Nat. Sc. Philad. 1854, p. 123. 

 ? Cymatogaster ellipticus, Gibbons, I. c. p. 124. 



