018 Bulletin 4j, United States National ATuseum. 



fits between the upper two rows. Eye close to the upper profile, 2 diam- 

 eters from end of snout, and 4 from extremity of opercle, its diametei 

 greater than interorbital width, (jtill opening wide; gill membranes 

 supported by very slender branchiostegals, confluent in front, and not 

 attached to the isthmus. The whole body and head are covered by 

 minute, smooth, imbricate, and adherent scales. All the dorsal spines 

 short, distant from one another, the first being above root of pectoral, 

 the last behind middle of lengtli of tail ; anal spines commencing imme- 

 diately behind vent, aud very gradually and but slightly increasing 

 in length behind, passing finally into flexible rays of varying and indefi- 

 nite number ; jiectorals inserted some distance behind the gill opening, 

 with A'ery narrow base; ventrals close to, but not extending to, the 

 vent; entirely separate. Color uniform light brown, blackish about the 

 gills and on the soft anal fin. Teeth minute, those of the upper jaw 

 scarcely different in size or shape from those of the lower, 31 on each 

 side of the upper and 23 on each side of the lower jaw, 21 in each half 

 of the palatine series; each ramus of the mandible with a series of pores 

 which is continued on the preoperculum. The union of the gill mem- 

 branes takes place opposite middle of distance between orbit and occi- 

 put ; orbit without circular fold. Gill cavity and peritoneal sac with 

 a thin layer of black pigment. Air bladder much smaller than in Nota- 

 canthus sexspinls, occupying a small portion of middle of abdominal 

 cavity ; anteriorly on the left side it is prolonged into a narrow cylindri- 

 cal horn about f length of its body ; there is no open communication 

 between it and the intestinal duct. The ovaries are a pair of band-like 

 bodies, transversely plaited and without oviduct. The intestine makes 

 only 1 convolution ; pyloric appendages rejjresented by 3 short diver- 

 ticula only. Kidneys confluent into 1 short body which is situated 

 between the muscles of the tail behind the vent. (Giinther.) North 

 Pacific. The type, 16 inches long, dredged by the Challenger at Station 

 237, south of Yedo, in 1,87.5 fathoms. A second specimen, 20 inches long, 

 obtained by Dr. Gilbert (Albatross explorations), in Bering Sea, west of 

 the Pribilof Islands, in 1,625 fathoms, at Station 3,308. (Named for Her 

 Majesty's Ship Challenger, employed in deep-sea research by the Govern- 

 ment of Great Britain.) 



Notacanlhus rUmamis, Gf'NTiiER, Fislies Challenger, xxii, Part i,vii, pi. i.xi, fig. B, 1887; not of 

 FiLLiPl & Veuany, Mem. Ace. Sci. Torino, xviii, lllO, 1859, whose speciiiieu canio from the 

 Mediterranean. 



Notacanlhus chalk'uyeri* Vaillant, Exjieaition Travailleur et Talisman, 1888, south of Yedo; 

 based on G('NTHEn'.s description. 



MacdonalfUa challewjcri, GouDE & Bean, Oceanic Ichthyology, 172, 1895. 



*" Vaillant was perfectly justified in separating this Pacific form from the Medit<'rranean 

 P(jlijacanlhi>w:vs riswanm, with whicL Jiintherhad identified it. The lower heavier siiines in 

 both dorsal and anal fins, the more anterior origin of the dorsal, which is a little in advance of 

 ba.se of pectorals, the very short robust ventral spine, and the lower insertion of pectoral fin 

 sufficiently distinguish the species, in addition to the peculiarities in the shape of the snout and 

 the greatly increased number of anal spines to which Vaillant calls attention. 



"Giinther's description, above cited, of the fish taken south of Yedo at a depth of 1,875 

 fathoms, agrees so well with our specimen that no do\ibt can exist of their identity. The max- 

 illary spine not shown in Giinther's figure, is very evident in our specimen. The branchioste- 

 gal rays are distinctly 6 instead of 5 in number, and the caudal contains 5 instead of 6 rays. 

 There are 35 dorsal spines. The anal spines pass so gradually into the rays that they are dis- 

 tinguishable with diffic\ilty. Definite articuhitions appear before the rays iiavo lost their spin- 

 ous character, while still stiff and pungent, liividing them on the basis of these articulations, 

 tho aaal fin coutaius 40 spines aud about 140 soft ravs." (Gilbert, MS.) 



