OSTEOLOGY OF CAULARCHUS M.EANDRICUS (GIRARn). 30 1 



heterocercy. The spines of one vertebra anterior to the hypural 

 assist in supporting the caudal fin. 



Stout ribs are present on all of the abdominal vertebrae except 

 the first one, and are continued back on the anterior caudal 

 vertebrae. They are vertically flattened and grow smaller pos- 

 teriorly. They project horizontally outward and to the lower 

 surface near the tip of each is a bony ray which curves down- 

 ward around the abdominal cavity. Gunther 1 describes these 

 as follows : "The epipleurals are not much less developed than 

 the ribs to the extremities of which they are suspended. We 

 might also consider the ribs as long and detached parapophyses, 

 and the epipleurals as the ribs proper." The presence of normal 

 parapophyses on the last abdominal vertebrae prove the latter 

 supposition to be incorrect, and if the distal bones are epipleurals 

 they have changed their usual position on the superior surface 

 near the bases of the ribs to the inferior surface near the tips of 

 the ribs. The only other possibility is that they are extra inter- 

 muscular ossifications as occur in some fishes, notably the 

 clupeoid fishes. 



No trace of a spinous dorsal remains, and there are no acces- 

 sory interneural rays in front of the soft dorsal. There are four 

 unbranched ventral rays, and a short flat bone hidden under the 

 skin in front of them representing a ventral spine, the rays are 

 thick and their cross articulations are very close as in the thick- 

 ened lower pectoral rays of the Cottoid fishes. I do not find in 

 either Gobicsox or Caularclnts the free ventral ray that Dr. 

 Gunther found in Chorisochismus dentex. 



The interspinal elements are normal in arrangement, and exactly 

 coincide in number with the vertebral spines to which they are 

 attached. No bony baseosts are developed. 



RELATIONSHIPS. 



The structure of the skeleton gives little help in assigning to 

 the family Gobiesocidae a definite phylogenetic position, and I find 

 myself no nearer to a solution of the problem than Dr. Gill was 

 when he wrote of these fishes in the " Standard Natural History," 

 (Vol. III., p. 267) as follows : " There are no spines in any of the 



'Cat. Fish. Brit. Mus., III., p. 493. 



