10 Verm, 
VERMES. 
AspidosipTion armatum^ sp. n. 
Onchnesoma glaciahy sp. n‘. 
Stephano stoma f g. n. Buccal disc very broad, with ten large groups 
of tentacles, between which are situated some isolated tentacles. Anal 
aperture immediately behind the base of the proboscis. S. hanseni, 
sp. n. 
Epithetosomatid^, fam. n. Body with a cylindrical hollow tube 
corresponding to the crop-cavity. Behind this, on each side of the 
anterior extremity of the body, is a fissure furnished with apertures at 
the bottom. No hook-bristles. 
Epithetosoma, g. n. Body cylindrical, furnished at its anterior end 
with a long non-retractile, tubular appendage (proboscis). Behind this, 
on the ventral surface, the round buccal aperture. On each side of the 
anterior extremity of the body a fissure, which is furnished with several 
apertures at the bottom ; no anal appendages ; anus at the posterior 
extremity of the body. E. norvegicum, sp. n. 
Priapulus pygmcEus and Thalassema viridis^-dely spp. nn., Verrill, Bull. 
U.S. Nat. Mus. ii. pp. 182 & 183. 
On the metamorphoses of Actinotrocha, see E. B. Wilson, Am. Nat. 
xiv. pp. 894 & 895. 
CH^TOGNATHA. 
46. Hertwig, O. Die Chaetognathen. Jen. Z. Nat. xiv. pp. 196-303, 
pis. ix.-xiv. (also separately). (For abstracts, see tom. cit, Suppl. 
Heft i. pp. 7-11, & 38-41.) 
This essay makes a very considerable contribution to our know- 
ledge of these animals ; after giving a history of the Chcetognatha, the 
author proceeds to — (1) their anatomy and histology ; (2) their classi- 
fication ; (3) their development ; and, in conclusion, he reviews their 
relations to the Ccelenterata and to the rest of the Vermes. With regard 
to the second of these points, it is only necessary to say that he recognizes 
Langerhans’s genus Spadella, with which he associates three species ; in 
the old genus Sagitta^ ten species are recognized. The importance of the 
mode by which the coelom in these forms is developed, is insisted upon, and 
it is pointed out that there is a radical difference between the two entero- 
coelic cavities bilaterally developed in them, and the radially arranged 
enteric prolongations which are developed in the Actinice. The resem- 
blances which exist between these two groups are shown to be due to 
the fact that certain fundamental laws are obeyed by all animals in their 
development. The points by which the Chcetognatha approach the Nema- 
toid Worms are also illustrated ; but their relations to the Annelids are 
shown to be still more marked ; no definite answer, however, is (or, as it 
seems, can yet be) given to the question whether these resemblances are 
analogical or homological. The sensory organs always retain their con- 
nection with the epidermis, as do also the chief ganglia and the nerves 
given off from them ; in addition, however, there are smaller ganglia 
which are embedded in the mesoderm, and appear to be derived from it ; 
these latter belong to the motor system. The muscular fibrils are not 
