SOME ABNORMAL ANNELIDS. 44.7 
terminal there are just 8, so that there are 27 + 8 = 35 seti- 
gerous somites in the main line, with a duplication of the 
posterior 8 arising between the 27th and 28th somites. 
Before speaking of the internal anatomy of this individual 
we may note that the other two, B and C, have almost the 
same character, the same oblique insertion of the terminals, 
but different numerical proportions. The specimen B has 23 
somites in the trunk, 12 in the right and 11 in the left ter- 
minal. The specimen C has only 18 somites in the trunk, 10 
in the left and 8 in the right terminal, which latter is broken. 
In all cases the terminals are all complete, as far as can be 
judged from an external examination of the general form, in 
proportions, parapodia, anal termination, and ventral nerve 
trunk. 
On studying the internal structure of A, by means of serial 
sections, we find at once that the two terminals almost exactly 
repeat the normal anatomy of the trunk, and are thus like 
two normal posterior ends of two normal Annelids. Each ter- 
minal has the normal digestive tract, nerve-cord, blood-vessels, 
and muscles, as well as sete and parapodia and even repro- 
ductive organs—the mother-cells of sperms. 
At the point of divarication the body-cavity and the digestive 
tract branch, as shown in fig. 12, which represents a median 
ventral section of the specimen A. 
Each terminal has its anal opening and its ventral nerve- 
cord extending forward from the anus throughout all its 
somites; but while the nerve-end of the ventral terminal is 
continued on as the ventral cord of the trunk, the nerve-cord 
of the dorsal terminal stops suddenly in the first somite, as 
shown in the figure. It thus appeared that the dorsal terminal 
was imperfect in having its nerve-cord imperfect in the first 
somite and without connection with the nerve-cord of the main 
trunk of the animal. A careful examination of the entire series 
of sections shows that this is probably the case. The nerve- 
trunk in the first somite is free from the epidermis, in which 
it normally remains in Podarke, and gives off large nerves 
along certain muscles which radiate upward from the nerve- 
