248 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
in the text. In a general way the form is that of a Chimaera with a long pro- 
boscis from the forehead. The amount of compression in the head and body is 
not very great; the body cavity is included in the anterior half of the total 
length; the head is massive, rather longer than the abdominal portion of the 
body, and has a long tapering rostrum which is subtriangular in cross-section, 
placed pretty well up on the forehead, flattened and provided with special 
sensory apparatus on the lower side, depressed and slender forward, and 
pointed at the end; the caudal region occupies half or more of the total length, 
is compressed and tapers regularly to a filamentary extremity, is encroached 
upon by the second dorsal fin, is surmounted in part by a low rudimentary fin, 
the upper edge of which bears an armature, and is subtended by a longer, 
deeper, and unarmed subcanudal fin. The skin is soft and smooth; there are 
four vertical fins and two pairs ; the anterior dorsal is erectile and has a strong 
serrated spine and distinct radials. ‘The length of the head is more than one- 
fourth, the length of the caudal section is about one-half, the length of the 
snout is little more than one-sixth, the depth is nearly one-tenth, and the width 
is nearly one-fifteenth of the total length. The oral portion of the head is 
prominent ; the mouth is similar to that of Chimaera. As in the other recent 
Chimaeroids, there are three pairs of the teeth, one of palatines, one of vcmer- 
ines and one of mandibulars, Plate 5, Figures land 2. Mere dot-like points, to 
be seen under a lens, on the sharp edges of the teeth, are the only approaches 
to tritors ; they have the appearance of the ends of small pores. By compari- 
son of the tongue figured on Plate 12 with those on Plate 5 and Plate 13. it will 
be seen that this organ attains a somewhat greater development in the present 
form. ‘The eye is large and is placed on the side of the head in such position 
as to command views outward, forward, and upward without hindrance. On 
the first and the second arches there are five well-developed gillrakers, with 
several rudiments; they are short, hardly one-sixth as long as the eye, and are 
acuminate; on the third arch and the fourth all of the rakers are more or less 
rudimentary. This individual, being a mature male, possesses a frontal ten- 
aculum, armed with about ten series of hooked spines, above the front edge 
of the orbit on the forehead. The back is nearly straight. The dorsal spine 
is situated above the bases of the pectorals; it is strong, has a narrow ridge in 
front, and is smooth on all edges with the exception of slight roughnesses on the 
hinder angles near the outer end, possible indications of sharp hooks on young 
individuals. Four rays appear in the first dorsal behind the spine, and a low 
membrane connects this fin with the second dorsal, which last rises gradually 
to less than half the height of the first and terminates abruptly more than twice 
the length of the eye forward from the origin of the upper fin of the tail. The 
upper caudal fin rises gradually, and, descending even more so, terminates 
more than twice the length of the orbit forward of the end of the tail, on this 
specimen. On the upper edge of this fin, which is somewhat rudimentary, 
there is a peculiar arrangement of small spines, Plate 4, Figure 2; a pair of 
larger ones are placed side by side and directed laterally, and behind each pair, 
between it and the next, there is a couple (1-3) of smaller spines placed longi- 
