264 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 
functional development of the claspers. Its teeth are represented by Figs. 6 
and 7 on Plate 5 of the present work. In number of plates and their general 
outlines these teeth are somewhat like those of a young Chimaera, but in 
regard to the tritoral surfaces they are very different. On the palatine and 
the mandibular teeth there are prominent series of tritors, like small rounded 
molars; on each of the palatines a series appears, the next to the outer, in 
which the tritors from the third counting backward are broadened into trans- 
verse bars, or in which two small tritors, or more, have united into one broad 
one. On each palatine tooth there are four more or less complete series of 
the tritors, the outer two or three of which are extended farthest backward. 
On the outer edge of each mandibular tooth there is a series of about ten of 
the tritors or cusps, and from the sixth and the seventh two shorter series 
extend back nearly parallel with the inner edge of the tooth. The vomerine 
teeth resemble in outline those of Chimaera. Medially in front each hooks 
downward in a sharp point; laterally from the point the edge lies higher and 
has three rounded tritors, the hindmost of which forms the hinder edge of the 
tooth. The claspers are but partially developed; they are short, without 
spines, stout and muscular at the bases, and in the distal three fifths of the 
length are slender, cylindrical, and rounded. The groove is distinct to the 
end. ‘The positions of the ventral tenacula are indicated by the openings, but 
within the tenacular cavities the organs are quite undeveloped; the spines, of 
course, are entirely absent. The frontal tenaculum, being of later develop- 
ment than the claspers, is not yet differentiated. Though there appears to be 
nothing on the sides of the forehead of this individual to distinguish it from a 
female, if looked at from above the shape of the tenaculum appears to be 
faintly outlined beneath the skin in its proper position. The dorsal spine has 
a sharp compressed keel on its front edge; it is triangular in a cross-section ; 
each of the hinder edges turns directly outward at the side, is sharp, and is 
barbed by sharp teeth hooking toward the base of the spine. At each side of 
the postorbital space on the crown there are three or four spines in irregular 
series, and there are four in longitudinal series at each side of the anterior 
portion of the base of the second dorsal. The upper margin of the third 
dorsal is like the others and has no such armature as that of Rhinochimaera 
pacifica (Plate 4, Fig. 2). 
The lateral line system resembles that figured on Plate 2, Figs. 3-5, from 
specimen 39415, but shows individual variation in several points. The upper 
rostral tract meets the lower at a short distance behind the tip of the snout; 
they pass into one another at each side of the rostrum. Behind the transverse 
band of sensory papillae or villi, on the left side of the lower surface of the 
snout the subrostral line extends back between the suborbital and the prenarial, 
but does not join with the latter like its fellow of the other side, and the pre- 
narial does not curve out to meet it. Behind the mouth on the chin the line 
is broken into dashes instead of being entire and transverse; similarly on the 
throat the transverse line is broken more or less, and is discontinued for a short 
distance about the middle. Below the middle of the supracaudal fin the lateral 
