70. ECHENEIDIDJE EHOMBOCHIKUS. 417 



Maxillary barely reaching vertical from nostril. Head 5 in length; 

 disk 3| ; width between pectorals about 7. D. XXI-XXY 32-41 ; 

 A. 34 (32-38). In all warm seas, north to Cape Cod and San Francisco. 



(Linn. Syst. Nat. ; Giiuther, ii, 384 : Leptecheneis naucrates Gill, Proc. Acad. Nat. 

 Sci. Phila. 1864, 60. Echeneis naucrateoides Zuieuw, Nova. Acta. Acad. Sci. Imp. Petro- 

 pol. iv, 279, Leptecheneis naucraleoides Gill, Proc. Acad. Nat. Sci. Phila. 1864, 61, Ech- 

 eneis albicauda Mitch. Amer. Monthly Mag. ii, 244. Echeneis lineata Holbr. Ichth S. C. 

 1860, 102, and Echeneis holbrooki, Giiuther, ii, 382, are names applied to specimens with 

 the disk comparatively long, but with only 21 laminae.) 



aa. Body rather robust ; vertebrae 12 + 15. (Eemora" Gill.) 

 I. Dorsal rays about XVIII-23. 



65 . E. femora L. Eemora. 



Uniform dark brown. Body and tail comparatively robust, the latter 

 compressed. Pectoral fins rounded, short, and broad, their rays soft 

 and flexible; ventral fins adnate to the abdomen for more than half 

 the length of their inner edge. Tip of lower jaw not produced into a 

 flap. Vertebrae 12 + 15. Head broad, depressed Disk longer than 

 the dorsal or anal fin. Maxillary scarcely reaching front of orbit. 

 Caudal lunate; vertical fins rather high; pectoral f length of head. 

 Head 4; disk 2f ; width between pectorals 5. D. XVIII 23; A. 25. 

 Warm seas, north to New York and San Francisco, usually found at- 

 tached to large sharks. 



(Echeneis remora L. Sysfc. Nat. : Echeneis jacoboea Lowe, Proc. Zool. Soc. London, 1839, 

 89: Echeneis remora Giinther, ii, 378: Eemora jacoboea Gill, Proc. Acad. Nat. Sci. Phila. 

 1862, 239.) 



aa. Dorsal rays about XVI-30. (Eemoropsis Gill.) 



659. E. brachyptera Lowe. 



Light brown, darker below ; fins paler ; body robust, the greatest 



depth nearly twice the length of the short pectoral fins; disk shorter 



than base of dorsal, rather broad; upper jaw angular. Caudal nearly 



truncate. Head nearly 4; width between pectorals G. D. XVI 30; 



A. 26. Warm seas, north to Massachusetts. 



(Echeneis brachyptera Lowe, Proc. Zool. Soc. Lond. 1839, 89: Echeneis quatuordecemlam- 

 inatus Storer, Hist. Fish. Mass. 406: Echeneis brachyptera Giiuther, ii, 378: Eemoropsis 

 Irachypterus Gill, Proc. Acad. Nat. Sci. Phila. 1864, 60.) 



2O7. RBIOMBOCH1KUS Gill. 



(Gill, Proc. Acad. Nat. Sci. Phila. 1863, 88: type Echeneis osteochir Cuv.) 



This genus agrees with Remora in every respect excepting the struc- 

 ture of the pectoral fins. These are short and broad, rhombic in outline, 



* Gill. Proc. Acad. Nat. Sci. Phila. 1862, 239 : type Echeneis remora L. (Eemora, an 

 ancient name, "holding back.") 



Bull. Nat. Mus. No. 16 27 



