TURBELLARIA. 
529 
(12. Moseley, H. N.) On Pelagonemertes Rollestoni. Ann. N. H. 
(4) XV. pp. 165-168, pi. XV. b. [b] On a young specimen of Pela- 
gonomertes Rollestoni. Op. cit. xvi. pp. 377-383, pi. xi. 
Anatomy and Physiology. 
McIntosh^s Monograph of the British Nemerteans (6) treats separately 
of the anatomy of the Enopla (pp. 43-94) and Anopla (pp. 95-124), 
elucidating for each division the cutaneous system, the body wall, the 
proboscidian sheath, chamber, and aperture, the proboscis, its different 
regions and special organs in the Enoplay its diversity of structure in 
different genera and species, and its' reproduction ; also the digestive, 
vascular, and nervous systems, the eye-specks, cephalic furrows and 
sacs ; the male and female generative organs, the mode of deposition 
of the ova and spermatozoa, and the developmental history of the 
Enopla and Anopla. Special chapters are devoted to the reproduction 
of lost parts, or of the entire organism from fragments, and to the 
parasites of Nemerteans. The “ homologies ” with Bipalium and Bala- 
noglossus are also discussed in special paragraphs, from the author’s 
own examination of both types. 
It is impossible to reproduce here an abstract or sketch of Nemertean 
structure as it is expounded in this work, the most complete of all. 
hitherto published on the group. It may be pointed out, however, 
that though the anatomical account is apparently almost exhaustive, 
the physiological value of important organs or structural peculiarities is 
still almost unknown : — e. g., the use of the cephalic slits and sacs, of 
the proboscis (which has never been seen used for any purpose, such 
as seizing the prey), and is very unfit for this use, and of the central 
stylet and the Isiteral stylet sacs in the Enopla, though it is certain 
that the sacs cannot have the object of replacing the central stylet ; 
and there is ho observation on record confirming the poisonous nature 
of the fluid in the reservoir and posterior chamber of the proboscis in 
the Enopla. Otoliths were never observed, nor were lenses or capsular 
structures discovered in the eyes. The numerous genital pores are placed 
above the lateral nerve trunks ; in some genera, the eggs are deposited 
in mucous masses secreted by the whole surface of the body. The vivi- 
parous and oviparous forms are connected by species, in which some of the 
eggs are deposited in the normal manner, while the remainder are developed 
in the slowly decaying maternal body. Some species show an acid, others 
an alkaline, reaction, when tested with litmus paper. The floating or 
swimming of certain Nemerteans is not due to the action of cilia. 
Hubrecht (5) draws attention to some discrepancies between the 
results arrived at by himself (4) and by McIntosh, who takes up the 
subject again in an anatomical account (7) of Amphiporus specta- 
hilis {= Drepanophorus, H.). The “cephalic sacs” are considered by 
Hubrecht as “a special respiratory apparatus providing the haemo- 
globin of the cephalic ganglia with fresh supplies of oxygen,” while 
McIntosh regards them as special organs of sense. The latter tenni- 
nates his paper with critical remarks on the papers of Willemoes-Suhni 
[Zool. Rec. xi. p. 500], Marion (9), and Moseley (11 & 12). 
1875. [vOL. XII.] M M 
