6 R. COLLETT. 
well as of its anatomical characteristics so far as they could be derived 
from the specimen, which in several respects was in an incomplete 
condition. In that account, the Author sets forth his views that his 
species is a type of an entirely new family, Chlamydoselachidae, 
which amongst fossil forms is most nearly related to Cladodus 
mirabilis, Agass. from Middle Devonian, and regards it thus as proved 
that the Cladodonts were true sharks, and that the primitive form 
connecting them with the fishes is to be sought further back in the 
Devonian or in the Silurian. 
The next contributions to our knowledge of this species was 
given by Dr. Giinther, who in 1887, in his large work on the reports 
of the deep sea fishes collected by the Challenger Expedition! gives 
supplementary details of its outward and internal construction from 
3 well preserved specimens, which were, likewise, obtained off Japan 
(Yeddo Bay, Tokio). Two of them were males, the longer being 
about 1474 mm., in length (thus about the same size as Garman’s 
typical specimen); the third was a female (eviscerated). 
Dr. Giinther’s remarks are accompanied by two plates, representing 
the species in a complete condition. The tail will be seen to terminate 
in a point, in conformity with those of most of the other recent sharks, 
whilst in Garman’s figure it terminated in a slanting line, as copied 
from a fractured surface. 
Furthermore various portions of the body are described, the 
construction of which could not be observed in the typical specimen. 
These were chiefly the two claspers, whose construction agreed in 
the main with that found in members of the family Notidanidae; 
and the stomach, liver, testicles, and conus arteriosus. Detailed 
descriptions are given, moreover, of the dentition, and show, inter 
alia, how the minute teeth in the inner series, differ very little from 
the enlarged papille of the surrounding skin. Each anterior series 
in these 3 specimens consisted of six, the posterior ones of five teeth, 
to which, generally, from 1 to 3 in an immature state of development 
are added. 
1 Report Scientif. Res. Voyage Chall. 1873—76, Zoology, Vol. XXII (1887). 
