Jordan : Fossil Fisuks from Riacho Dock. 31 



n some specimens, crushed under the opercle in others. Preopercle pre- 

 served in one or two examples only, normally formed, rather large, but 

 not expanded, its angle about a right angle. Some shining bones or plates 

 on top of head. Vertebrae 17 + 13 = 30 (to 32), those of the caudal 

 portion relatively few, the caudal region barely half as long as the ab- 

 dominal region. Distance from snout to nape rather more than from 

 nape to front of dorsal. 



Dorsal rays not to be accurately counted, about 12 in number, perfect 

 in one specimen, Number 71. very high, twice as high as long; anal rays 

 apparently about 12. Ventrals well developed, about as large as pectorals, 

 inserted below front of dorsal, and distinct in all specimens, the rays 

 apparently 8. Pectoral short, placed low. Body marked with depres- 

 sions, the imprint of small rounded scales, these about 50 in a linear series. 

 Anterior interspinal bones of dorsal and anal better developed than usual 

 in herrings. Caudal long, sharply forked, the lobes equal, i-g in head. 

 No trace of ventral nor of dorsal scutes. No trace of finlets behind anal. 

 Ribs short; rather straight, about 19 in number. 



The type of this specimen mentioned is pressed flat in black shale, the 

 head interiorly crushed, and not clearly shown. Its salient traits are its 

 form, the development of its ventral fins, the absence of the scutes so well 

 developed in Brazilian species of Diplomystus, the development of its 

 interhaemals and the shortness of the ribs and the large size of the opercle. 



Besides No. 91, here figured, we have 92, its duplicate, equally well 

 preserved, aj inches 'ong. No. 112, also figured (Plate IX, fig. 12), is 

 very small, scarcely more than an inch long, and Numbers 67, 68, 69, 71, 

 72, 73. 75. 76, 77. 74. 78, 82, 86, 87, 84, 88, 89, 90, 91, 93, 94, 95, 96, 97, 

 102, 103, 105, 107, no. III, 112, 113, 118, 119, 120, 121, 122, 123, 124, 

 126, 127, 128, 129, 131, 132, 133, 134, 195, 196, 197, 198, 199, 200, are of 

 various sizes up to 3 inches, and in fair condition of preservation. In 

 Number 71 the dorsal fin is well preserved, and is unusually high, twice 

 as high as long, the longest ray nearly as long as head. In Number 195, 

 a crushed head, the opercle and preopercle are conspicuous. This speci- 

 men we figure (Plate IX. fig. 11). In Number 200 (Plate IX, fig. 10) 

 the head is lost, but the body is very well preserved and the scale imprints 

 are very evident. We figure this specimen also. In many specimens 

 the large opercle, crushed and dislocated, smooth and shining black, is 

 conspicuous. 



Broken fragments, mostly identifiable by the large opercles, or by the 

 ventral fins, are the following Numbers: 135, 136, 137, 138, 139, 140, 143 



