DESCRIPTION OF AN ANTARCTIC SPECIMEN 9 



Bertelsen points at, contribute to pull the tentacle forwards. The remaining two pairs of muscles are 

 the erectors and flexors of the illicial ray at its joint with the distal end of the basal bone. In Ceratias 

 these muscles are relatively small, but they are large and powerful in Gigantactis. Movement of the 

 lure in Gigantactis is mostly at the level of the illicial ray, but in Ceratias at that of the basal bone. 



The musculature of the lure in the new specimen has been examined. The precise attachments to the 

 basal bone of the exsertors, retractors and inclinators could not be determined, since the lure had 

 already been removed on preservation. But these three pairs of muscles appear virtually as described and 

 figured by Bertelsen, to whose paper reference should be made. The black integument of the exserted 

 part of the basal bone has been either torn or digested away, and the muscles of the illicial ray have 

 suffered in this damage, so that only the flexors of this ray can be clearly distinguished at the joint with 

 the basal bone. When the fish was found the illicial ray dangled vertically, making an acute angle with the 

 inclined basal bone (PI. I) ; damage to the illicial erectors would presumably account for this condition. 



The black integument of the illicial ray of the new specimen is expanded distally into a pear-shaped 

 esca (Fig. 4C). About the middle of this bulb the black pigment changes to a dull blue and then gives 

 place to a distal unpigmented region, until the pigment is resumed again as a small disk at the extreme 

 tip of the organ. Two short filaments, pigmented for about half their length, spring from this black disk 

 which is also pierced by a round pore (Fig. 2A). The fixed material shows some jelly-like exudate in 

 the pore ; this may be the erstwhile luminous mucus which such an open type of luminous gland might 

 be expected to release. This particular esca has not yet been examined histologically, but Dahlgren 

 (1928) sectioned the esca of a specimen of Ceratias and described it as an open gland wherein light was 

 produced by a culture of bacteria which filled most of its lumen. 



A terminal pore appears also to be characteristic of the escas of species of Mancalias as figured by 

 recent authors (Regan & Trewavas, 1932; Imai, 1941), and it is significant that Bertelsen now regards 

 the genus Mancalias as synonymous with Ceratias. The arrangement of the pigment on the esca of 

 the new specimen agrees closely with that given for the escas of Bertelsen 's Greenland specimen and 

 Kroyer's type (Bertelsen, 1943). The incidence, number and arrangement of filaments on the esca have 

 been assigned some specific value by most systematists of the Ceratioidea. With regard to C. holbolli 

 Regan's incomplete specimen does not assist in a comparison of the escal filaments, but Bertelsen, who 

 has re-examined Kroyer's type, states that both his own Greenland specimen and the type agree in 

 bearing only one terminal filament, whereas the Antarctic specimen has two (Fig. 4C and D. Fig. 4D 

 is from Gaimard ; the base of this esca appears to be torn). What validity this difference may or may not 

 have as a taxonomic character will be discussed later. 



THE CARUNCLES 



On the back of the new specimen, close behind the dorsal tentacle, there are situated two club- 

 shaped structures. They lie close about the middle line, the right a little forward of the left. These 

 organs are the caruncles. They are black and glandular in appearance and 0-6 cm. high. Each bears 

 a terminal pore. A sharp spine protrudes from the tip of the right caruncle, and a spine can be palpated 

 in the other where its presence is betrayed as a slight bulge on one side (Fig. 2B). The presence of these 

 spines supports Rauther's conclusions that the caruncles are modified fin rays (Rauther, 1941). 



Kroyer, Rauther (1941) and Bertelsen all mention the presence of similar club-shaped caruncles in 

 their specimens of C. holbolli. Regan (1925 a, b, 1926) does not mention the caruncles in his specimen. 

 It is clear, as Bertelsen has pointed out, that among the three genera of the Ceratiidae, Regan (1926) 

 and Regan & Trewavas (1932) regard only Cryptosparas and Mancalias as possessing caruncles, and not 

 Ceratias. However, careful examination of Regan's specimen reveals the presence of two black sessile 

 bodies lying among the spines posterior to the peduncle of the damaged dorsal tentacle. They are 



