522 Miscellaneous. 



genetic importance to it ; but being occupied with, other investiga- 

 tions he did. not follow up his observations, and refrained from 

 publication. Haddon also has described and figured it for certain 

 Opisthobranchs, but does not seem to have observed it in the Proso- 

 branchs he studied. 



The region between these two bands is occupied by numerous 

 very fine cilia, which, as in the PolifgorcUus-lauVvaL, are continuous 

 with those lining the mouth-opening and the oesophagus. The ar- 

 rangement of cilia which is to be found in the typical Annelid larva 

 is therefore almost exactly reproduced in the Gasteropod Yeliger. 



Arguing from ontogeny, a phylogenetic history of the Gastero- 

 pods somewhat as follows may be constructed. They and the 

 Annelida have had their origin in a Trochophore. In the Gastero- 

 pods this ancestor developed a univalve shell, represented by the 

 larval shell so often replaced as development proceeds by another 

 more ornamented and more complicated in structure. The develop- 

 ment of this shell, by increasing the specific gravity of the animal, 

 rendered the simple praeoral cilia of the Trochophore insufiicient for 

 active locomotion, and the extent of the band was increased by the 

 region of the body on which it occurred being as it were pulled out 

 laterally, the characteristic velum being thus produced. Perhaps, 

 too, in the presence of the shell, a reason can be found for the- 

 absence of metameric segmentation in the Gasteropods. — Johns 

 Hopkins University Circulars, Oct. 1885, p. 5. 



Results of a Faunistic Excursion in the Iser-, Miesen-, and Glatzer 

 Gehirge. By Dr. Otto Zachaeias. 



"With the aid of subventions from the Berlin Academy and the 

 Silesian Society the author has made a second excursion in the region 

 of the Iser-, liiesen-, and Glatzer Gebirge, and obtained some inter- 

 esting results, especially in relation to the Turbellaria. He has 

 ascertained positively that, as indicated more than fifty years ago by 

 Draparnaud, Dalyell, and Duges, at certain times reproduction by 

 spontaneous transverse division takes place in many freshwater 

 Planarians. In the Iser Gebirge he has found a Pohjcelis cornuPr, 

 apparently identical with that described by 0. Schmidt (Zeitsehr. 

 wiss. Zool. X. I860, pp. 25, 26), Avhich propagates exclusively by 

 transverse division. In a brook near Hirschberg he obtained Pla- 

 naria tentacidata, Drap. (already observed by Duges), which for 

 weeks together reproduced by simple division, or rather by ter- 

 minal gemmation. In this Planaria he ascertained by serial sections 

 that there was not the smallest trace of either male or female 

 sexual organs. He states, however, that during the autumn indi- 

 viduals occasionally appeared in which distinctly diff'erentiated 

 sexual organs were recognizable. 



Dr. Zacharias has also investigated the minute anatomy of the 

 Turbellaria, especially with respect to the exact course of the two 

 lateral nerves and the innervation of the pharynx. His investiga- 

 tions were made upon a new species described by him under the 

 name of Monotus relictus (Zeitsehr. wiss. Zool. xli. 1885, p. 505). 

 In this species he succeeded in ascertaining the whole course of the 

 lateral nerves (from the cerebral ganglion to the posterior extremity 



