ANNELIDA. 
605 
organ ; cocooiis heinisplieric, flattened on the side of attachment, covered 
with stiff curled hairs, and furnished with an extensive transparent border. 
Sp. H. solece. 
Fam. Heterobdellid^. 
Hetei’ohdella pallida ; II. scillii. 
Fam. H 1 STR 10 BDELLID.E. 
SaccohdeUa, n. g. Body rounded, presenting a cephalic enlargement and 
a median one which protects the sexual organs, and within which the 
entire caudal extremity can include itself by invagination. Two stalked, 
sheathing, posterior suckers. Sp. S. nehalice. 
Fam. MALACOBDELLIDiE. 
Malacohdella cardii. 
GEPHYREA. 
Semper, among other anatomical notes, comments on some 
points of interest in the structure of Thalassema and Sipunculus. 
His remarks chiefly refer to the generative and vascular systems 
of these worms, and to the larval form Actinotrocha. 
Semper also describes certain peculiar organs which he has 
found in the integument of a few Sijmnculi, scattered over the 
general surface, but especially numerous towards the posterior 
end. Each consists of a rounded vesicle enclosing four smaller 
vesicles disposed around a central nerve. The nerve appears to 
terminate in a cellular expansion at the point of the vesicle, 
whence also four pairs of filamentous bands (muscular ?) 
originate, and become lost among the smaller vesicles. Exter- 
nally the larger vesicle supports a horny ring furnished with 
three teeth. Upon these bodies a tactile function probably 
depends. [Op. cit. pp. 419-421.) 
New species : — 
Phascolosomum exasperatum, Stimpson ; Stemaspis affinis, St. 
PERIPATUS. 
We have already noticed the position assigned to Peripatus by 
Van Beneden. Schneider {op. cit. p. 593) states that the 
muscular system of this genus, both in minute structure and 
general arrangement, resembles that of the Hirudinea. Ehlers 
{op. cit. pp. 12-14), on the other hand, suggests affinities 
between Peripatus and the Tardigrada, 
SAGITTA. 
Ehlers {op. cit. p. 11) has no hesitation in referring Sagitta 
to the Nematoids. Schneider recognizes its near affinity to 
these worms, but would still retain for its reception the order 
Ch(Btognatha (R. Leuck.). 
