46 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



of their relative lengths. Anal spine very slender, and about half the length of the soft rays. 

 The caudal is injured, but appears to have been of nearly the same form as in the U. arenata. 

 The pectorals are about three-fourths the length of the head, but the ends of the rays are 

 worn. The ventrals are of the same length as the pectorals in their present state : they are 

 placed rather backwarder than in the U. arenata, being attached beneath the first third of the 

 pectorals : there is a pointed scale in their axilla, of about the same relative size as in that 

 species. The scales on the body are rather smaller, ciliated on their free edges, with a fan of 

 eleven or twelve striaj behind. There are rows of small scales on the caudal, but none apparent 

 on the other fins. 

 Colour. — Mr. Darwin did not notice the colours of this species in its recent state. In spirits, it 

 appears of a nearly uniform dusky brown, but paler on the abdomen, with traces of silvery 

 reflections about the head. The fins are dark, but the anal paler at the base than at the tips 

 of the rays. 



Habitat, Coquimbo, Chile. 



This species may be at once distinguished from all those described in the 

 ' Histoire des Poissons,' by its very elongated form. The head also has a 

 peculiar character about it, and is not unlike that of some serpents. It appears 

 to be the first species of this genus brought from the Pacific, the other foreign 

 ones being all found either in the Indian seas, or on the Atlantic side of America. 

 There are two specimens in the collection, exactly similar, and both obtained by 

 Mr. Darwin at Coquimbo. They are, however, both in very bad condition ; so 

 much so, indeed, that I should have hesitated about describing them as new, had 

 they not presented several obvious peculiarities. 



Genus— PRIONODES.* Jen. 



Serrani formam quam maxime gerens. Pinna dorsalis vmica, per tolam longitudinem 

 subcequalis. Membrana branchialis septem-radiala. Nee fovea, nee port, infra 

 symphysin. Dentes maxillares velutini, serie externa ceteris fortiori, paucis, hie 

 illic sparsis, subcaninis; palatini nulli. Preoperculum denticulatum. Operculum 

 mucronibus tribus postice armatum. Spina analis secunda forlis . Squama corporis 

 ciliattB ; minutissimce inter radios pinnarum verticalium, in seriebus dispositce. 



I am called upon either to establish this new genus among the Scicenidce, or 

 to break down one of the essential distinctions set by Cuvier between this family 



* Sense figuram habens. A irpiwv. 



