10 
Crassicauda 
tissue, in which the head is found. It is easy, therefore, to understand the 
difficulty hitherto experienced in obtaining an unbroken specimen of Crassi- 
cauda. The nodules, formed in the dense tissue of the penis or in other solid 
tissues, effectually prevent it from being pulled out; while its tortuous course 
renders the task of dissecting out the worm, without cutting it, a very difficult 
one, especially if the surrounding tissue has been hardened by reagents. 
Mr Bennett succeeded, by cutting out one of the hard nodules (A) with 
the worm, in extracting the latter entire, and on examination it proved to 
be a male C. crassicauda (Crepl.). Anterior portions of females, almost certainly 
of the same species, were also obtained. This material enables some further 
details to be added to the description of C. crassicauda. The writer (1916, 
Fig. 1. Diagram, adapted from a drawing by Mr Bennett, of an excised portion of the penis of 
Balaenoptcra, with a specimen of Crassicauda crassicauda in situ. The upper part of the draw¬ 
ing is in transverse section. In the lower part, the skin has been cut longitudinally over the 
urethra and reflected on either side. The urethra is represented as slit open longitudinally, 
c., cavernus core of corpus cavernosum;/., fibrous sheath of corpus cavernosum; s., skin of penis; 
u., urethra; X, caudal end of worm hanging freely in urethra; A, B, successive nodules 
formed by the worm. 
1920) has published some notes on the anatomy, but the characters of the 
anterior end were still very imperfectly known. The cephalic papillae of a 
specimen thought to be C. crassicauda were described in the former paper, 
but in the second it was shown that at least two species exist, and this rendered 
the conclusions of the first less certain. In the light of the material now 
received, which is proved by the characters of the male tail to be C. crassi¬ 
cauda , it is possible to say that the characters of the head previously described 
agree with those of C. crassicauda. It is not, of course, possible to say whether 
they differ from those of C. boo pis, which is only certainly known from 
headless specimens. The accompanying figures (Figs. 2 and 3) show that the 
same papillae are present, and that they are arranged in the same way, as 
in the head of which an “ en face ” view was previously (1916) figured. 
