218 PEECT SLADEX TRUST EXPEDITION, 



advance of the pectorals ; li or 15 photophores in the lower series from ventrals to 

 anterior part of aual and 11 or 12 in the series from middle of anal to caudal. Upper 

 series of photophores 36 or 37 in number, running from above the pectoral to above the 

 middle of anal. Dorsal 13 ; origin above the ventrals, equidistant from occiput and 

 base of caudal, inal 15, its origin some distance behind the end of the dorsal. Greyish ; 

 peritoneum blackish. 



Plankton, II, 750-0 fathoms, near Desroches Atoll. 



A single specimen, 110 mm. in total length. 



Evidently closely allied to the Astroiiesthes elucens of Brauer, which differs in the 

 larger eye (6| in the length of the head in a specimen of 146 mm.) and in having 

 only 22 j)hotophores in the upper series, which terminates above the ventral fins. 



I have named this species after Dr. A. Brauer, in recognition of his recent work on 

 the deep-sea fishes of the ' Valdivia ' expedition. 



2. Chcmliodus sloaul, Bl. Schn. 



Plankton, N, 600-0 fathoms, north of Pei?os Atoll. 



3. Melanostomias caldivice, Brauer. 

 Plankton, s, 500-750 fathoms, near Farquhar Atoll. 



A specimen of 60 mm. has only 10 teeth in the posterior maxillary series instead of 

 28 as in the larger specimen (165 mm.) described by Brauer. 



4. Argyropelecus affinls, Garm. 



Plankton, s, 750-1000 fathoms, near Farquhar Atoll 



5. Argy )'opelecus sladeni, sp. n. 



Depth of body \^ in the length, length of head 3|. Two spines at the angle of the 

 praeoperculum, one directed downwards, the other backwards. Dorsal and abdominal 

 ridges not serrated ; no spines on the caudal peduncle. Post-abdominal photophores in 

 3^grou2:)s, 1 between ventrals and anal, 6 above the anal fin, 4 on the lower edge of 

 caudal peduncle; supra-anal series separated from the praeanals by a very short interr 

 space and from the caudals by a distance equ.al to f the length of the supra-anal series. 

 Dorsal 9. Anal ? Pectoral as long as the head. 



Chagos Archipelago, Salomon, 1-00 to 500 fathoms. 



A single specimen, 28 mm. in total length. 



Five species of Argyropeleciis may now be regarded as well established, all of which 

 are represented in the British Museum Collection ; they may be distinguished as 

 follows : — 



I. Photophores forming a nearly continuous series 1. offinis, Garm., 1899. 



II. Postabdominal pliotophores in 3 groups — prseanal, supra-anal, and caudal. 

 A. Dorsal and abdominal ridges serrated ; a double series of spines 

 on the lower surface of caudal peduncle ; prseoperculum with 

 a single downwardly directed spine 2. aculeatits, C. St V., 1849. 



