of the Island of Trinidad, W. I. 391 



described by Drs. Muller and Troschel are the P. Sellonis, P. Ste- 

 gelicliii, and P. Deppei. It is the P. Deppei that we have alluded 

 to in our remarks on the geographical distribution of the genus, 

 as being the only species that has been discovered beyond the 

 boundaries of the South American zoological province ; that 

 species, according to Drs. Muller and Troschel, was brought by 

 the gentleman to whom it was dedicated, M. F. Deppe, from 

 the Sandwich Islands, but from what particular island we are 

 unfortunately not informed. The discovery of a representative 

 of this group in those Islands is most interesting, and we may 

 well look forward to the time when our knowledge of their 

 fresh water fishes will be increased, as an archipelago that has 

 contributed to the malacologist so many species of most interest- 

 ing genera peculiar to the Islands, will doubtless afford some 

 interesting ichthyic novelties. 



Pimelotus Vilsoni, Gill. 



Vernacular: Catfish; Barbe. 



This species is one of the most slender of the genus. Of the 

 entire length from the snout to the termination of the lobes of 

 the caudal fin, the head to the end of the operculum bears a 

 proportion of only one to about five and two thirds ; the visible 

 portion of the posterior projection of the interparietal of Cuvier 

 and Valenciennes, or the supra-occipital of Owen, extends a 

 very short distance beyond the operculum. The cranium is 

 irregularly wrinkled, the wrinkles becoming more prominent, 

 posteriorly. The anterior " fontanelle," or " solution of con- 

 tinuity," is elongated and narrow, extending from a point on a 

 line between the inner angles of the maxillary barbies, as far 

 back as the posterior borders of the orbits. The eyes are large 

 and longitudinally oval, and the longitudinal diameters are con- 

 tained between four and five times in the length of the head, 



