This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated.1879 Excerpt: ... Tho apparent segmentation of the form leads the author to inquire as to the possibility of his having had to do with a larval Annelid; all these forms, however, seem to agree in that they do not exhibit niotameric segmentation till a late period, and at any rate not until they have developed setro at points corresponding to, and apparently indicative of such segments; while tho presence of sexual products in the forms observed militates against their being immature. Nor again does the metamerism seem to be due to gemmation, nor is it the first instance of such an arrangement; Busch recorded a case in 1851, the characters of which were in 1865 put by MetschnikofF in their true light, while the Russian naturalist took this opportunity of recording another example. The form appears to belong to the Microstomece. The most interesting points in a new species of Proetomium (P. boreale) are the presence of a chitinous sabre-shaped spine, which is placed to one side of the penis, and appears to be an organ either of defence or offence, and of a collection of glandular bodies of uncertain function, set on either side of the base of the proboscis. In another new species (P. paptllatum) Mereschkowsky observed the presence of six papilliform projections at the anterior end of the body, which serve undoubtedly as tactile organs. In a new species of Mesostomium, which he dedicates to L. Graff, Mereschkowsky describes the presence of enlargements on the vessels, which did not however exhibit either contraction or pulsation, and the function of which remains obscure; they do not seem to have been hitherto observed in these forms. The author also makes some remarks on Dinophilus vorticoides, Oscar Schmidt, and on the general Turbellaria-Fauna of the White Sea. Digestive Org...