10 DISCOVERY REPORTS 



0-4 cm. high, and each bears a small pore. They are undoubtedly caruncles. Although more widely 

 separated than those of the Antarctic specimen, the right caruncle still lies slightly in front of the left 

 (Fig. 2C). The presence of caruncles may now be accepted as a character of all members of the 

 Ceratiidae without exception. Their possible significance will be discussed later (p. 19). 



THE VISCERA 

 Kroyer made brief reference to the internal organs of Ceratias. The viscera of Ceratioid dwarfed 

 males have received attention from Regan (19250) and from Parr (1930). The first complete account of 

 the anatomy of a Ceratioid fish, however, is given by Waterman (1948) in his description of Gigantactis 



longicirra. 



The following notes on the viscera of the new specimen are limited to what could be seen after 

 a single median incision into the body cavity (Fig. 3). 



The short wide oesophagus leads into a moderate stomach of somewhat caecal type. The cardiac 

 stomach expands into equal pyloric and caecal portions, the latter being posterior. Externally the 

 stomach appears compact, but its internal lining is strongly thrown into some twenty longitudinal folds. 

 Doubtless this allows the stomach to accommodate large or numerous prey. Moreover, as Waterman 

 has observed on Gigantactis, the coelom is large and has room for a distended stomach. 



The duodenum leaves the stomach anteriorly and medianly, and passes right where it receives two 

 pyloric caeca of somewhat unequal size. Kroyer mentions these two caeca in Ceratias, and it is 

 interesting that Waterman found none in Gigantactis. At the junction of the pyloric caeca the duodenum 

 expands to a wide, thin-walled tube which then receives the bile duct. The intestine passes back, 

 suspended by its mesentery in overlapping loops, along the length of the stomach on the right-hand 

 side until it narrows again, somewhat abruptly, level with the posterior end of the stomach. This 

 narrower part, which presumably should properly be called the large intestine, is fairly long, and for 

 the most part lies looped behind and above the stomach. It terminates in a short, straight, rectal 

 portion. This gut differs from that of Gigantactis by its looped character and the inversion of the usual 

 difference in size between small and large intestines. However, Waterman's specimen of Gigantactis, 

 3-9 cm. long, is doubtless an immature individual, and the relatively greater length of gut in Ceratias 

 may probably be attributed to greater size and age rather than to a real morphological difference 

 between the two genera. 



The liver is of moderate size and bi-lobed. Waterman found an additional small third lobe in the 

 liver of Gigantactis. The hepatic ducts of Ceratias unite to form a common duct which then divides 

 into a large bile duct to the duodenum and a long and equally conspicuous cystic duct to the gall- 

 bladder. This organ is large and lies dorsal to the stomach and posterior to the liver. Ceratias closely 

 corresponds to Gigantactis in this arrangement. 



The pancreas is a very finely diffuse, arborescent structure, lying in the mesentery between the 

 hepatic portal vein and the gut. This agrees with Waterman's description of the pancreas in Gigantactis, 

 except that in Ceratias it can be traced farther forward, beyond the hepatic portal, as far as the loop 

 between the duodenum and the pyloric stomach. Posteriorly the pancreas of Ceratias is bounded by 

 the posterior mesenteric and its associated intestinal vein. 



The spleen is a subspherical body of median size, lying slightly forward of the bile duct in the 

 mesentery between duodenum and liver. In Gigantactis Waterman found it below the posterior part 

 of the intestine — a less typical position for the teleost spleen. 



There is no swim-bladder. This confirms Kroyer's observation. Waterman, likewise, found no 

 swim-bladder in Gigantactis, and the absence of this organ may well be characteristic of the Ceratioidea, 

 as it is of many other groups of bathypelagic fishes (Rauther, 1937). 



