{h) A larger fish in counterpart (Fig. 10), with tlic ventral border 
displaced downwards. 
Sp. Char . — A species closely resembling L. talhracjaren sis, hwi^mfxWov 
and more slender. The head with opercular apparatus is elongated, about two- 
thirds as deep as long, and its length is equal to the maximnni depth of the 
trunk. 
LEl’TOLEriS GUEGAIMIJS, Sp. UOi:. 
Plate TY, Figs. S-10 ; Plato Y, Fig. 5 ; Plate YJ, Figs. 11, 12. 
Ohs . — The numerous specimens referred to this species ate all small, 
and hear a mark of immaturity in the circumstance that the vertebral rings 
are narrow and separated by considerable spaces. The proportions of the head, 
however, and the less remote situation of the anal fm, distinguish the fish 
from the associated species just described, and no intermediate forms have 
been observed. It may thus receive the sjiecilic name of L. gregarius, in 
allusion to the shoals in which it usually occurs. Of the numerous specimens, 
the following six are selected for illustration : — 
{a) The type specimen, shown of tlie natural size in PI. IV, Pig. 8. 
The vertebral rings are crushed so as to appear in end view, and the 
abdominal region is slightly deepened by the displacement of the 
ventral margin. 
{h) More imperfect fish (PI. IV, Pig. 9), displaying the caudal vertebne 
in side view. 
(c) Specimen showing minute teeth on the maxilla, some of these greatly 
enlarged in PI. IV, Pig. 11. 
(d) Slab Avith slioal of lishes in various states of preservation (PL V, 
PVg. 5). 
(c) Pish shown in PI. VI, Pig. 11, and bones of head diagrammatically 
outlined in PI. lY", Pig. 10. 
(/) Specimen somewhat decjAened 1)V distortion and rvith vertebral rings 
shoAvn in end view (PI. Y"I, Pig. 12). 
The diagrammatic outline of the head given in PI. IV, Pig. 10, shows 
the form and proportions of the opercular bones and cimiial roof, Avith the 
parasphenoid in side view, and the suprateni])oral plate and clavicle ; but 
appearances in the region of the jaAVS are partly deceptive. The mandible, 
