3'28 Prof. Owen's Desci-iption of the Lepidosiren annectens. 



compared with the head and the extremities, — a difference which is quite 

 independent of age or growth ; and the character, " pedes valde distantes," 

 which Dr. Natterer has founded on the length of the trunk, must be restricted 

 as a specific application to the Lepidosiren paradoxa. 



Dr. Natterer obtained two specimens of his species ; one of these, which 

 measured upwards of three feet in length, was found in a swamp on the left 

 bank of the Amazon, above Villa Nuova ; the other, which was nearly two 

 feet long, was taken in a pond near Borba, on the river Madeira, a tributary 

 of the Amazon. The specimen about to be described, though differing appa- 

 rently from the L. paradoxa only in certain proportions of its outward form, 

 is a native of a different continent, and was taken in the river Gambia*. 

 It is a female, with the ovaria well-developed, and measures twelve inches, 

 eight lines in length : its greatest circumference is four inches and a half f . 

 The head commences by an obtuse muzzle, and gradually enlarges in all its 

 dimensions to the gill-openings, which are situated immediately anterior to 

 the base of the pectoral extremities : the length of the head from the snout to 

 the gill-opening is one inch, eleven lines; the trunk, from the pectoral to the 

 ventral filamentary fins, is five inches, five lines. The anus, or rather the 

 cloacal vent, is a small elliptical aperture marked with radiating lines, which 

 is situated three lines behind the ventral filaments, and offers the same pecu- 

 liarity as does that of the Lepidosiren paradoxa in not being situated on the 

 median plane : in the present specimen it was on the right side of a longitu- 

 dinal fold of integument which occupied the middle line. The distance from 

 the vent to the end of the tail is five inches. The trunk gives a wide ellip- 

 tical transverse section;}:, and maintains a pretty uniform size, slightly de- 

 creasing in breadth to the ventral filaments. Beyond these the tail becomes 

 more rapidly compressed, and, after a short distance, diminishes also in verti- 

 cal dimension, till it ends in a thin point. 



A membranous dorsal fin commences at the distance of four inches from 



* It was presented to the Royal College of Surgeons, June 1837, by Thomas C. B. Weir, Esq., 

 together with a smaller dried specimen inclosed in indurated clay, baked hard by the sun. Several 

 species of insects, peculiar to the Gambia, or African forms, accompanied these specimens. It is here 

 described and figured by permission of the Museum Committee of the College. 



t Tab. XXIII. figs. 1. & 2. J lb. fig. 3. 



