GEMPYLIDAE, LEPIDOPIDAE AND TRICHIURIDAE 25 



TRICHIURUS. 



A specimen of T. Upturns from Jamaica, 32 inches in length; a 

 head and partial skeleton of a slightly smaller skeleton from Virginia, 

 and a head and shoulder girdle of a specimen, about the same size as 

 the first, with the species and locality unknown. 



In the first specimen the sutures separating the cranial bones are 

 well marked and the clavicle is normal. In the second specimen the 

 frontals, parietals, epiotics and supraoccipital have become covered 

 with spongy bone substance, thickening them and uniting them into a 

 single piece. The clavicle is normal. In the third specimen the frontals 

 have become anchylosed, but not thickened, and well marked sutures 

 separate the other bones. In this specimen the lower part of the clav- 

 icle is very much swollen, so much so that the usual deep channel along 

 its posterior edge is filled in. This bone thickening does not appear 

 to be of the same character as that of the cranial bones of the second 

 specimen, where the thickening appears to be a superficial, soft, cellu- 

 lar deposit. In the clavicle the surface of the swollen portion is the 

 same as that of the unmodified portions, as if it were a regular peri- 

 osteal deposit.* 



The skeleton of Trichiurus scarcely differs from that of Lepidopus. 

 The front of the skull is nearly devoid of ridges extending forward 

 from the supraoccipital. The supraoccipital extends more broadly over 

 the epiotics than in Lepidopus, appearing to widely separate them, 

 though they meet within the cranial cavity. 



The suborbital ring is represented by the preorbital and one ossicle 

 behind it, with a third at the posterior margin of the eye unattached to 

 the others. The last is developed inward as a thin wing, so that it is 

 apparently the suborbital shelf, but shifted backward from its po- 

 sition in Lepidopus. There is no suborbital sensory tube. 



The maxillary elements and lateral face bones are identical with 

 those of Lepidopus. The teeth differ only in being larger and occupy- 

 ing deeper pits. The hypocoracoid is not broad and produced back- 

 wards abnormally, and the postclavicle is more slender. The shoulder 

 girdle and its attachment is otherwise as in Lepidopus. The pelvic 



*I have examined a number of specimens in the collections of Stanford Uni- 

 versity for a similar condition of the clavicle, and find it only in a specimen from 

 China labeled Trachiurus japonicus. This condition may be of enough importance 

 to separate its possessors into another genus. It is apparently a condition parallel 

 to that of Melanogramnus, which has been separated from Gadus by a similarly 

 swollen hypocoracoid. Sufficient material is not at hand to decide whether it is a 

 development with age. 



