DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 73 



dorsal base is two-tliinls that of head. Oiisiu of ventral under tenth scale of. lateral line; 

 it does not reach to vent. Pectoral short, its lenyth nearly two-thirds that of head. Adipose 

 dorsal present; its origin over thirtieth scale of lateral line. Anal origin under eighteenth 

 scale of lateral line; the end of its base under thirtieth scale. Length of ajial base equals 

 that of head. Caudal is rather small and moderately forked. 



Mediolateral photophores three, in straight, obliquely ascending line; anterolateral one; 

 posterolateral one, under soft dorsal and over and slightly in advance of break in row of 

 superanals, which is above root of la stray of anal. Number of superanals 8+G. 



In most of the specimens of M. opaliitum examined , the G or 8 scales on the top oi' tlie 

 caudal peduncle, immediately in front of the caudal tin, are luminous. 



MYCTOPHUM PHENOODES, (Eitkkn), (iooi.K ;iiid I'.ran. 

 Scopclits }>hcnc/0(ks, Li'TKEX, Spolia Atlantica, ii, 1892, 253, Fij;. 11. 



A species resembling in general appearance our Myctophum punctatum, from which it 

 is distinguished by having a long, falcate pectoral, tlu^ tij) of which extends almost to the 

 vertical from the vent, ami is neai-er to the row of mediolateral i>hotophores than to the 

 anterolateral. This form has, as in .^^. pniiettdiim, the posterolateral considerably in advance 

 of the soft din-sal, and has the precaudal photophores much farther apart (a character upon 

 which some stress is laid by Liitkeii, but which seems to us of le ss iuii)ortauce than the 

 position of the posterolateral photophore). Number of superanals, G-7 + 7-U. 



Eadial formula: D. 12; A. 21; L. lat. .'58. 



Liitken had it from the Atlantic, south of the eipiator, presumably irom surface. 



MYCTOl'HUM IIUMBOLDTII (Iv'lsso). (Figure S2.) 



Gantcroprlecus Jlitmholdii, Risso, Icth. Nii-i'. S5S, jil. 10, fig. 38. 



Scopchis lliimholdti, Ris.-iO, Mem. Accad. Sc. Torino, xxv. 1820, 206, \<\. ID, fig, 2. — (liiNTiiEii, Cat. Fish. Brit. 

 Mus., V. 407.— GiGLlOLi, Eleni-o, 100, 



Height of body is oinvflftli of total length (without caudal), length of head two-sevenths. 

 Least depth of tail two-flfths of height of body; depth of head If in its length. Diameter 

 of eye a little less than one third of length of head; distance between posterior margin of 

 orbit and preopercular edge one-half diameter of eye. Snout short, obtu.se, its upper pro- 

 file descending in strong curves Maxillary reaches nearly to angle of preoperculum, and 

 slightly dilated behind. Origin of dorsal somewhat nearer to end of snout than to root of 

 caudal, above root of inner ventral rays; its last ray before vertical from origin of anal. 

 Pectoral extends to posterior third of ventral. Scales smooth, stiff. Mediolateral photo- 

 phores, 2; anterolaterals, 2; posterolateral, 1, (over break in anal series) which, as in M. 

 punctatum, is considerably in advance of the vertical connecting the root of the soft dorsal 

 with those of the last rays of the ainrl. Caudal photophores somewhat apart as in 31. phen- 

 f/odi's. Superanals 7-9 + 4-9. Radial formula: D. 12-14; A. 20-22; L. lat. 40-42. 



This species was first described from the Mediterranean about Nice, but appears to b(! 

 rare. The British Museum had specimens from the eastern Atlantic. The Albatross 

 obtained a specimen (No. 43772, U. S. N. M.) upon the surface, at 7 p. m., from station 2727, 

 in 30O 3.>' N. lat., 74° 03' 30" W. Ion., and also a very fine specimen (No. 43773, U. S. N. M.) 

 from station 2724, in3(ia47' N. lat., 73^ 25' W. Ion., at a depth of 1,641 fathoms. 



Liitken had a numl)er of specimens of M. HumhohUii (op. eit., p. 254, fig. 2) from the 

 following localities : N." lat. 34° 20', W. Ion., 183 30'; N. hit. 12° 12', W. Ion. 28° 48'; S. lat. 

 70 C', W. hm. 11=30'; S. lat 33'= 30', W. Ion. 11 =; S. lat 37^ 40', E. Ion. 78° 34'; S. lat. 37=, 

 E. Ion. 50 ; S. lat. 39° 54', E. Ion. 41 = 30'; S. lat. 29^ 30', E. Ion. 12°; S. lat. 2.5O40', E. Ion. 

 230 ; S. lat. 120, E. Ion. 103^ 50' ; S. lat. 11 ^ 15', E. Ion. 103° 50' ; N. lat. 10° 40,' E. Ion. 110^. 



Liitken unites M. hoops with M. Hiimhohltii. but since the latter has been as yet fouml 

 only in the iKU-theastern I'acific, we prefer to hold them apart until specimens from the two 

 oce^ms have been studied side by side. The scales in lateral line are said to number 37-9. 



