FISH. 4 ° 



Mr. Darwin obtained one specimen only of this new genus at Chatham 

 Island in the Galapagos Archipelago. It is probably not full-sized. 



Pristipoma cantharinum. Jen. 

 Plate X. 



P. caruleo-argenteum, operculo nigro-marginato : pinna dorsali subaquali, spims 

 ultimis radiis articulatis paulo brevioribus ; anali spina secundd forti, longitudi- 

 naliter striata, radiis articulatis duodecim : preoperculo rectangulato, margine 

 adscendenti, leviter denticulato, basali integro : verlice, buccis, et ossibus opercula- 

 ribus, squamatis; rostro ultra nares, suborbitalibus, et maxillis, nudis ; squamis 

 corporis ciliatis : pinna caudali f areata. 



B. 7 ; D. 12/15 ; A. 3/12 ; C. 17, et 4 breviores ; P. 20 ; V. 1/5. 



Long. unc. 10. lin. 11. 



Fo*M.-Form oblong-oval, much resembling that of the Cantharus griseus. Body compressed 

 with the dorsal line slightly curved ; the profile descending from the nape more obliquely, and 

 in a very regular manner. Greatest depth beneath the commencement of the first dorsal, 

 contained not quite three times and three quarters in the entire length : head rather less than 

 one-fourth of the length. Mouth protractile, but not wide, the commissure not extending to a 

 vertical from the anterior angle of the eye; when closed, the maxillary retires beneath the 

 suborbital, and only just the extremity remains visible. Jaws equal ; in each a narrow band of 

 velutine teeth, the outer row somewhat longer than the others, particularly above, where they 

 approach to card. Tongue, palatines, and vomer smooth. Eyes moderate ; their diameter 

 rather less than one-fifth of the length of the head ; rather nearer the extremity of the snout 

 than the posterior margin of the opercle ; the distance between them equalling twice then- 

 diameter. Two small pores and a fossule beneath the symphysis of the lower jaw, the latter 

 very distinct. Preopercle rectangular, the angle somewhat rounded ; the ascending margin 

 nearly straight and finely denticulated, but the denticulations hardly continued to the angle, 

 and not appearing at all on the basal margin. Opercle with two small flat points, but very 

 indistinct and almost lost in the membrane. Suborbitals large, with their lower margins entire. 

 Crown, cheeks, and pieces of the gill-cover, covered with small scales; but not the snout in 

 advance of the nostrils and eyes, nor suborbitals, nor lower jaw. Suprascapular marked by a 

 large scale, the margin of which is nearly entire. 



Lateral line following the curvature of the back at one-third of the depth ; each scale 

 marked with an elevated line without ramifications. A scale taken from above the lateral line 

 ia of a somewhat rhomboidal form ; the free portion very finely striated, with the margin finely 



H 



