INVERTEBEATA, CRYPTOGAMIA, mCROSCOPY, ETC. 793 



12-14tla rings ; tlie testes are stalked, and the seminal glands have an 

 " amorphous form " ; by these two points the new species is distin- 

 guished from Pachydrilus, while, by the presence of red blood, it is 

 remarkable among other species of Enchytrceus. 



Batrachobdella Latasti,* — M. Viguier has now published in full 

 his account of the organization of this form (see this Journal, ii, p. 

 885). The author is of opinion that in it, and doubtless also in 

 Clepsine and its allies, the tactile and gustatory sense-organs are to be 

 found in the proboscis, which has a very rich plexus of nerves. There 

 are only two eyes, and these are i)laced close to one another ; they are 

 irregularly quadrangular in form. 



The author has some doubt whether the single si^ecimen of Glossi- 

 pJionia alfjira, which Moquin-Tandon was able to examine, and on 

 which he founded the species, was not really a large Batracliohdella. 

 Bearing in mind that the specimens he himself was enabled to examine 

 were not fully mature, and that the two sj^ecies have the same habits 

 and inhabit both the same region, he concludes by throwing out the 

 suggestion that M. Taudon's form was really a Batrachohdella, and 

 that the new specific name of Latasti may have to yield to the prior 

 appellation of algira. 



The Chsetognatha.'f — Oscar Hertwig publishes a monograph of 

 rather more than one hundred pages (and five plates) on these very 

 instructive " worms." 



The author commences by directing attention to the deep signifi- 

 cance which must be given to the two modes by which various 

 animals develop their coelom or body-cavity ; in the greater^number 

 of animals this coelom is formed by a cleavage of the mesoblast, 

 and to this Professor Huxley has applied the name of schizoccele ; 

 others, such as the Echinodermata, Brachiopoda, and Amphioxus, 

 together with the Chfetognatha, develop theii- ccjelom from outgrowths 

 of the endoblast, and to this form Huxley has given the name of 

 enterocoele. 



It is now ten years since Kowalevsky placed these differences on 

 the firm ground of observation, but, important as these diiferences 

 are, they have hitherto been hardly regarded with sufficient atten- 

 tion ; to what results they may lead us will be best illustrated by 

 stating at once the general conclusions to wliich Dr. 0. Hertwig has 

 been led. 



Relations of the Chcetof/natha to the Codenterata. — The Actinia) by 



(1) the development of diverticula from the primitive cntcron, and 



(2) the physiological and histological characters of these parts, 

 exhibit many striking relations to the Chfctognatha. It is at a very 

 early stage in devcloi)mcnt that the arclienterou of Smjitta bec<jmes 

 divided into three cavities, or, in other words, jn-ovidcd with two 

 lateral diverticula ; a septum of an Actinian and an endoblastic fold 

 of a Sagitta arc comparable structures, inasmuch as both have for 



* ♦ Arch. Zool. cxp. ct Rcn.,' viii. (1880) p. .373. 

 t 'Jen. Zcibchr.,' xiv. (1880) p. 11)0. 



