360 ENTOZOA. 
At the end of this order I also place an animal which ap- 
proaches it in several respects, but which may one day serve 
as the type of anew one. It forms a genus which I have named 
NEMERTEs, Cuv. 
It is an extremely soft and elongated worm, smooth, slender, flat- 
tened and terminated at one extremity by a blunt point, pierced by 
a hole; the other end, by which it fastens to its prey, is widened and 
very open. Its intestine traverses the whole length of the body. A 
second canal, probably connected with the process of generation, 
serpentines along its parietes and terminates in a tubercle on the 
margin of the wide opening. Messrs d’Orbigny and de Blainville, 
who saw the animal while alive, assure us that the wide aperture is 
its mouth. . 
N. Borlassi, Cuv.; Borl., Cornw., X XVI, 12, is more than 
four feet in length. It remains buried in the sand, and, it is said, 
attacks the Anomiz which it sucks in their shell(1). 
In the vicinity of Nemertes should probably be placed the 
TupuLaria, Renieri, 
Equally large and extremely elongated, but furnished with a small 
mouth opening under the anterior extremity. 
OPHIOCEPHALUs, Quoy and Gaym. 
With the same form but the extremity of the mouth cleft. 
CEREBRATULA, Renieri. 
Which scems only to differ in the greater shortness of the body(2). 
(1) For this singular worm, which is mentioned by Borlasse only, I am indebted 
to M. Dumeril who found it near Brest. It is the genus Bonzasia of Oken; M. 
Sowerby had previously called it Linevs, 
(2) We have neither seen the Tubularia nor Cerebratula. The names of Tu- 
bularia and Ophiocephalus, being already applied to other genera, cannot subsist. 
