LARVAL AND POST-LARVAL FISHES— REGAN. 127 



the head, so that the migration of the anus l)ack\vai'(l,s during the development of 

 this species is estal)lished. 



Moreover, it is evident that Pri/niiitiflinnus is not a vahd genus, liut merely a 

 larval form of Xotolepix, Paralejm, etc. 



The capture of this example in the Ross Sea comjiletes the evidcnrc that Xnfolepis 

 rtiiitsii is ciri'umpoljir, for it had previously been taken near Peter Island, at the 

 Soutli (h'kneys and in tlie Weddell 8ea, and near Wilkes Land. 



Myctophum, sp. 



Some specimens, very much damaged, taken on March 27tli, 1'.)12, at Station 

 238 ; 52° 11' S., 1G7'' 25' E., 80 metres. 



The largest, 13 mm. long, is very similar to the somewliat larger example of 

 J/, punctatum, Rafiu. figured by Holt and Byrne (Fisheries Ireland Sci. Invest., 1910, 

 VI, pi. I, fig. 1), but difi'ers in that the anal papilla is separated Ijy an interspace from 

 the anal fin. I count 40 myotomes and 20 anal rays ; the dorsal fin appears to have 

 been bitten off". 



Myctophum (mfdniicitoi, (luntli. (PI. I. figs. 1-3). 



A number of examples of this circumpolar species, 10 to 18 mm. in length, were 

 taken in the Subantarctic Zone at Stations — 



235 . 52° 41' S., 168° 15' E., 10 metres, March 26th, 1912. 



238 . 52° 11' S., 167° 25' E., 30 ,, March 27th, 1912. 



240 . 51° 57' S., 167° 38' E., 4 ,, March 28th, 1912. 



250,251 54° 2' S., 177° 0' W., surface, Dec. 20t]i, I9l2. 



252 . 54° 33' S., 176° 55' W., ,, Dec. 21st, 1912. 



308 . 55° 29' S., 78° 54' W., 4 metres, April 9th. 1913. 



In adult examples, 60 to 100 mm. in length, I count 13 to 15 dnisal and 18 to 

 22 anal rays, and 40 to 42 myotomes. I find the same numbers in the larger 

 specimens (14 to 18 mm.) of the "Terra Nova" collection, wliich have the fin-rays 

 developed, but diflfer from the adult fish in the following points : — 



(1) There are no scales or photophores, except a single photophore on each side 



above the base of the pelvic fin. 



(2) The dorsal and anal fins are lower, the caudal fin is less emargiuate, the 



adipose fin is longer, and the paired fins are shorter. 



(3) The fish is more elongate, and the snout is proportionately longer, the eye 



smaller and the maxillary shorter, not reaching the vertical from the 

 posterior edge of the eye. 



(4) There is a prominent anal papilla, and from it a membranous fringe runs 



forward to the base of the pelvic fins. 



(5) There is a small sinus, subdivided by septa, persistent above the occipital 



T 2 



