2 Journal of the Asiatic Society of Bengal. [N.S., XVIII, 
In Labeo rohita the sides of the neural arches of the first 
vertebra are incomplete. There is a wide gulf between the 
paratus—the claustrum and the scaphium—bridge over this 
gulf and in a dried skeleton almost complete the neural arch 
of the first vertebra. The scaphium has always been homo- 
logized with the neural arch of the first vertebra, but the claust 
rum has been regarded either as a neural spine of the first verte- 
bra or asa part of the skull. In Labeorohita and also in several 
other Cyprinoid fishes that I have examined, the first vertebra 
possesses a distinct neural spine and so the claustrum evident- 
ly cannot represent that structure. As regards the second 
view, I have not been able to find any evidence from an exa- 

; -FIG. 1--Front view of first vertebra in Labeo rohita showing 
relative positions of claustrum and scaphium. n.s.! = neural spine of 
first vertebra; n.a.| = neural arch of first vertebra; ¢.p.1 = transverse 
process of first vertebra; t.p.2 = transverse process of second vertebra: 
el. = Claustrum ; sc. = seaphium. 
mination of the occipital region of the skull that the claustrum 
once formed a part of it. Iam of opinion that the claustrum 
is another piece of the neural arch of the first vertebra. Its 
very position strengthens my conclusions. 
The intercalarium has usually been regarded as a modi- 
fied neural arch of the second vertebra, but Sagemehl! was 
of opinion that it represented the rib of the second vertebra. 
intercalarium is Serta a part or whole of the neural arch of 
the second vertebra 
1 Sagemehl, Morphol Jahrb. X, p: FT (1885.) 

ee te et Bee eee ae lr 
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