CHLAMYDOSELACHUS ANGUINEUS. 5 
to find anything which might be considered at all near. In Cladodus 
of the Devonian, there is a form with teeth somewhat similar .... 
However, the type is one which produces the impression that its 
affinities are to be looked for away back, probably earlier than the 
Carboniferous, when there was less difference between the sharks and 
the fishes.“ 
Garman’s views as to the relationship of the new species pro- 
duced, during the course of the year, a discussion between him and 
a few of the American ichthyologists, who however finally agreed in 
the main with the conclusions of Dr. Garman. 
Thus Professor Cope (Science, March 7 1884) pointed out that 
Chlamydoselachus belonged directly to his genus Didymodus, ,which 
had hitherto been supposed to be confined to the Carboniferous and 
Permian period,“ and in conformity to his views, he named it in his 
next treatise (American Naturalist, April 1884) Didymodus anguineus. 
In two reports (Science, March 21" and April 11" 1884) Professor 
Gill declared himself to be so far of Cope’s opinion, that he asserted 
that Chlamydoselachus did have a representative in the Carboniferous 
genus Diplodus, Agass. (= Didymodus, Cope), but was convinced, 
not only that the last genus had no generic or even family relations 
with Chlamydoselachus, but that it represents even a different order. 
On the other hand, according to his opinion, Chlamydoselachus was 
not either closely related to Chladodus, as assumed by Garman. In 
a fresh treatise (Science, May 30" 1884) Professor Cope abandoned 
his position concerning the affinities of the two genera Diplodus 
(Didymodus) and Chlamydoselachus, chiefly on the ground of the 
construction of the dorsal fin, but he, nevertheless, continued to be 
of the opinion (Palzeontol. Bull. No. 38. July 1st 1884) that the difference 
in the dentition was not greater than that the two relations in that 
respect should be regarded as one. , This is an interesting discovery, 
indicating that this genus, and not Ceratodus, is the oldest type of 
vertebrate now known in a living state.“ 
After having published several minor contributions explanatory 
of his new species, in reply to the observations of Professors Cope 
and Gill, Garman published, in 1884, a new and detailed account of 
the specimen (Bull. Mus. Comp. Anat. Harv. Coll. Vol. XII, Cambr. 
July 1885), accompanied by a series of plates which represented the 
most important features of the outer construction of the species, as 
