'•■'.i. SVXODOM1S. 215 



11. Synodontis xiphias. 

 D. 1/7. A. 11. P. 1/10. V. 7. 



The upper jaw terminates in a long, conical pointed process, the 

 length of which is two-ninths of that of the head. The height of the 

 body is two-ninths of the total length (without caudal), the length of 

 the head one-third. The gill-opening extends downwards to before 

 the root of the pectoral fin. The intermaxillary teeth form a broad 

 band ; the mandible has' two sets of different teeth : anteriorly a 

 short series of small flexible teeth, and posteriorly on each side a 

 minute patch of villiform teeth. The maxillary barbels extend some- 

 what beyond the end of the head, and are slightly compressed, but 

 not dilated ; the outer mandibulary barrels reach to the base of the 

 pectoral, and are provided with filaments. Nuchal carapace coarsely 

 granulated, tectiform, considerably longer than broad. Dorsal spine 

 very strong, much compressed, as high as the body, granulated in 

 front, serrated behind, and striated on the side. Pectoral spine ser- 

 rated along both edges, shorter than that of the dorsal fin ; humeral 

 process more than twice as long as broad, pointed behind, the point 

 being slightly directed upwards. The distance between dorsal and 

 adipose tins is much more than the length of the base of the former. 

 The length of the adipose fin is one-fourth of the total (without 

 caudal). Caudal deeply forked. Small round brown spots are risible 

 on the head and on the adipose fin. 



"West Africa. 



a. Twenty-eight inches long : stuffed. Purchased of Mr. Dalton. 



II. The gill-opening extends downwards to the throat. 



12. Synodontis membranaceus. 



Pimelodus membranaceus, Geaffr. Descr. E<j. Toiss. pi. 13. figs. 1 & 2. 

 Synodontis membranaceus, 7s. Geoffr. Poiss. Xil, p. 160; Cuv. 8f Vol. 



xv. p. 258. 

 batensoda, Riippell, ForUetz. Beschreib. neuer Nil-Jische, p. 0. 



taf. 3. fig. 2 (barbels not good). 



D. 1/7. A. 12. P. 1/9. V. 7. 



The gill-opening extends downwards nearly to the middle of the 

 throat ; mandibulary teeth very short and small, forming a minute 

 patch. Maxillary barbels shorter than the head, lined with a very 

 broad black membrane. Dorsal spine not serrated in front ; humeral 

 process as long as high. The adipose fin commences immediately 

 behind the dorsal. Belly black. 



Upper Nile. 

 a-h. Fine specimens, 20 inches long. Chartoum. Prom Consul 



Pethcrick's Collection. 

 c. Young. Chartoum. From Consixl Pethcrick's Collection. 



