DESCRIPTION OF AN ANTARCTIC SPECIMEN 5 



inwards. They are slender, sharply pointed and small, the longest measuring 0-4 cm. In the dentary, 

 and especially near the symphysis, they tend to be arranged in two series, the inner series including the 

 longest teeth. This character is contained in the synopsis of the family given by Regan & Trewavas 

 (1932). The teeth in the premaxillary are mostly smaller, and there is less indication of a second series. 



The dental formula is — . — . In Regan's specimen the shape and arrangement of the teeth are the 



8 8 



same, and relatively they are the same size, the largest being o-6 cm. in length. Their formula is . 



24 23 



The difference in the number of teeth is not considered significant in the two specimens since, as 



Waterman (19396) has pointed out, there are at present no data on the individual and ontogenetic 



differences in the teeth of Ceratioids. 



The gill opening, in both the new and Regan's specimen, is an oval aperture immediately below and 

 a little posterior to the insertion of the short peduncle of the pectoral fin. 



There is close correspondence between the fins of the new specimen- and those of Kroyer's type and 

 Regan's specimen. As in these the dorsal fin has four rays. There are no ventrals. The small pectoral 

 fins have nineteen rays each in the new specimen and in Kroyer's type. Regan's specimen has eighteen 

 pectoral fin rays. All three examples have four rays in the anal fin. Kroyer gives eight rays for the 

 caudal fin of C. holbolli, and Regan & Trewavas (1932) also define eight rays for the family, Ceratiidae, 

 although Lutken (1878) and Gill (1878) stipulate nine and Regan (1926) allows eight or nine. Beebe & 

 Crane (1947) find an incipient ninth ray in some of their specimens of ' Mancalias aranoscopus ' . The 

 caudal fins of the new specimen and of Regan's have eight rays and the four middle ones are forked 

 (Regan & Trewavas, 1932). But the caudal of the new specimen, like that of Saemundsson's 1939 

 example (see Bertelsen, 1943), is damaged and does not possess the ribbon-like prolongations found in 

 the type and in Regan's specimen. 



Smallness of the eye has long been recognized as a character of deep-sea angler fish, especially the 

 Ceratiidae (Kroyer, 1844; Lutken, 1878; Gill, 1878; Giinther, 1887; Regan, 1912 and Waterman, 

 1948). In describing his monospecific genus Typlopsaras, Gill (1883) gives 'obsolete or no eyes'. 

 Typlopsaras was included with Mancalias by Regan & Trewavas (1932) and has since been regarded as 

 a juvenile Ceratias by Bertelsen (1943). Gill does not clarify these remarks on the eyes in his description 

 of the single specimen Typlopsaras myops. The eyes of the new specimen, besides being small, are 

 especially interesting because they are subcutaneous. In the region where one would expect to find the 

 eye there is a ring of black pigment, stippled with minute spines. This ring encloses a small circular 

 area, 0-4 cm. across, where the skin is transparent and forms a kind of eyeless window. When first 

 examined two small blood vessels could be seen to cross its floor (Fig. 1 A). The eye itself is completely 

 concealed below the normal opaque skin, in a position immediately dorsal and adjacent to the pig- 

 mented ring; it may be exposed by an incision. Undoubtedly the specimen was functionally blind. 

 I have found that the eye is also subcutaneous in Regan's specimen, although he has apparently over- 

 looked this in his very brief accounts of the fish itself (1925a, b, 1926), being naturally preoccupied with 

 dwarf-males. As would be expected, his photograph of a cast made from the specimen (19256) shows 

 no trace of the eye. In Regan's specimen the disk of transparent skin surrounded by a ring of pigment 

 is not to be found. The figures of Kroyer's type displays a small eye (Gaimard, 1842-56, Poissons, pi. ix). 

 Bertelsen 's text does not mention the eyes in the two specimens he describes, but no eye is visible in his 

 photograph of Saemundsson's 65 cm. example. Significantly enough, the eye may be discerned in his 

 much smaller 18-5 cm. specimen recovered from west Greenland in 1880. This matter of the eye will 

 be discussed later (see p. 15). 



Nostrils have not previously been described in Ceratias. They are present as much reduced structures 



