102 TELEOSTEI : ACANTIIOPTERI. — XX. 



DISCOCEPH ALT. — Of these various suborders, we noti'ee first 

 Uu' DiscocKi'MALi, a small group characterized by a singular modi- 

 fication of the dorsal fin. 



Family L. ECHENEIDID^. (The Remoras.) 



Body fusiform, elongate, with minute smooth scales ; mouth wide, 

 with villiform teeth; lower jaw projecting. Spinous dorsal changed 

 into a sucking disk placed on top of head and composed of a double 

 series of transverse movable cartilaginous plates. Opercles un- 

 armed, P. placed high. V. I, 5. D. and A. long, similar; gill- 

 rakers short ; no pseudobranchiaj ; no air-bladiler. Vertebrae more 

 than 24. Genera 3, species 10. Of the opt-n seas, attaching tliem- 

 selves to sharks, sword-fishes, tunnies, and floating objects, and thus 

 carried for great distances in the sea. The relationships of this 

 group are still uncertain. Their resemblance to Elacate is such that 

 tlu'y apparently should not be placed very far away from the next 

 family, 

 a. Body slender; vertebrx 14 -f- 16 = 30 ; disk of 21 to 25 laminae; not more 



than i body Echeneis, 117. 



aa. Body robust; vertebra; 12-^15=27; disk more than J body, of IG to 18 

 lamina'. 



b. IV'cloral rays normal, soft Remora, 118. 



lb. IVctoral ray< stiflf, broad, ossified Riiombociiikus, 119. 



117. ECHENEIS (Artedi) Linnaeus, (exfvrits, an ancient nanae 



iiH-aning one who holds shij)s back.) 



2.04. E. naucrates L. Si'cking-kish. PKdAnou. Blackish, 

 Ix'lly dark ; a black lateral stripe ; corners of C. pale. Head .0^ ; 

 disk 3§, shorter than D. ; width between P. 7i. D. XXT to XXV- 

 82 to 41. A. 32 to 38. L. 30. Warm seas. N. to Cape Cod; 



the commonest species, on sharks, etc. (Eii.). (favKpdrqs, pilot.) 



118. REMORA Gill. (Ancient name, meaning one who holds 



back.) 



a. Dorsal about XVIII-23. {Remora.) 



2.')5. R. remora (L.). Rkmora. Sucking-fish. Uniform 

 dusky; head 4 ; disk 2|, longer than D. ; width between P. 5^. A. 

 25. L. 12. Warm seas, N. to N. Y. (Eu.) 

 aa. Dorsal about XVI -30. (Remoropsis G\\\.) 



256. R. brachyptera (Lowe). Swoun-Fisn Rkmora. Light 

 brown. Head 4; disk shorter than dorsal; width In'tween P. (J^. 

 A. 2G. Warm seas, rarely N. ; on sword-fish, (^paxvs, short; 

 trrrpof. fin.) 



119. RHOMBOCHIRUS Gill. (p6ix$ot. rhomb; ;^,.'p. hand.) 

 •J..7. R. osteochir (C uvii-r). Spkau-fisii Rk.moka. Liirht 

 brown ; mouth small ; disk very large. Head 5 ; disk 2^ ; width 



