296 



Transactions. — Zoology. 



Kt'H to the Species of Regalecus. 



A. More than 250 dorsal rays. 



a. Teeth present : a caudal fin (?). 



a. Height = J^ length 



b. Teeth absent : no caudal fin. 



a. Height = T V length : D. ^~ 

 /3. „ = T V „ D.406... 



B. Fewer than 250 dorsal rays. 



a. Teeth present (?) : a caudal fin (?). 



D _ 8 8 



XJ ' 1275 TTTO" 



b. Teeth absent. 



4—5 



a. A caudal fin: D. — — ... 



223 



jo. No caudal fin. 



i. Height = Jj length : D. ^fg 



ii — l D 15 



11 • " — T75 " ■ L/ * 190 



1. R. gladius. 



2. R. telwm. 



3. ii. banksii. 



4. i^. grillii. 



5. R. (jlesne. 



6. -R. russellii. 



7. i2. pacificus. 



8. E. argenteus. 



EXPLANATION OF PLATES XXIII. AND XXIV. 

 Plate XXIII. 

 Fig. 1. Eegalecus argenteus, side view of the head (J nat. size). 



br, branchiostegal rays : d. 2 1 , first ray of 2nd dorsal fin : e, eye : fr, preorbital 

 process of frontal bone : g, gills : is, isthmus : i.op, inter-opercular : Ic, lachrymal 

 bone : l.l, lateral line: mn, mandible: mx, maxilla : na, nostril : op, opercular : 

 pc.f, pectoral fin : p.e, par-ethmoid (pre-frontal) : p.mx, pre-maxilla : p.op, pre- 

 opercular : pv. f, pelvic (ventral) fin : r. 7, seventh, and r. 9, ninth rays of crest : 

 s.op, sub-opercular. 

 Fig. 2. Regalecus argenteus, distal portion of 7th ray of crest (nat. size) ; x, point at which 



membrane became broken. 

 Fig. 3. Regalecus argenteus, transverse section through the body, at about the middle 

 (| nat. size). 

 d.f, dorsal fin : g.c, gastric ceecum : h.a, hasmal arch, enclosing caudal artery and 

 vein : l.l, lateral line : n.a, neural arch, enclosing spinal cord : r.r, tuberculated 

 ridges: v, centrum of vertebra. 



Fig. 1. Head of R. pacificus \ 



Plate XXIV. 

 after von Haast. 



2. Tail „ „ j 



3. Head of R. banksii, after Hancock and Embleton. 



4. „ „ (?), from Gray. 



5. „ „ (?), „ 



6. ,, R. gladius) 



_ m ., . [ after Cuvier. 



7. Tail of „ ) 



8. Head of R. glesne ) 



n m ., I from Yarrell, after Schneider. 



9. Tail „ „ j 



