NOTES AND MEMORANDA. 199 



round the vessels, and they become finally also lined by lamellar 

 bone-substance. 



These observations of Professor Schwalbe are of great interest 

 with reference to the pathology of rickets, inasmuch as there 

 exists a definite relation between this disorder and the stage of 

 osteoporosis above mentioned. The examination of rickety 

 bones proved (1) an imperfect filling out of the osteoporotic 

 shaft with lamellar substance; (2) a new deposit of embryonal 

 bone-substance by the osteogenetic layer of the periosteum on 

 the surface of the cortex. So that in rickets the periost con- 

 tinues to form bone on the embryonal type, while the formation 

 of lamellar substance in the cortex proceeds only slowly or im- 

 perfectly .^ E. Klein. 



Salensky on the Polyzoa Entoprocta. — When preparing 

 the abstract of Vogt's paper on Loxosoma, which was pub- 

 lished in a late number of this Journal, I was unacquainted 

 with Salensky^s researches on the Entoprocta which have 

 recently appeared in the ' Annales des Sciences Naturelles.'® 

 The paper in which they are recorded takes much the same line 

 as that of Vogt, and is in some measure complementary to it, 

 and I propose to give a brief account of its most interesting 

 points. 



Salensky^s investigations were conducted at Naples, and were 

 undertaken, he tells us, for the purpose of comparing the gem- 

 mation of the Entoprocta with that of the Ectoprocta, and so 

 determining the relations which exist between the structure of 

 these two groups. Two species of Loxosoma were examined, 

 which he believes to be new ; L. crassicauda, Salensky, living as 

 a commensal on a species of Annelid, and L. Tethya, Salensky 

 which occurs in immense quantity on the TetTiya, and on them 

 only. The former belongs to that section of the genus which 

 is destitute in the adult condition of a pedal gland ; it possesses 

 eighteen tentacles, and is not attached by an expanded disc. It 

 is also furnished with numerous, strongly developed unicellular 

 glands in the integument, which strike the eye at once. The 

 author believes that the mode in which the peduncle of L. 

 crassicauda is attached is a specific distinction, but in this point 

 it agrees with L. Phascolosomatum, Vogt, which is also destitute 

 of an adherent disc, and is fixed by a special secretion. 



^ The abstract in the last number of the Journal (January, 1878) of 

 Professor Boll's paper on nerves, as well as that of Professor Bizzozzero 

 and Salvioli, have been ascribed, by error, to me. They were prepared by 

 Dr. John Cavafy. 



'^ " Etudes sur les Bryozoaires Entoproctes," par M. Salensky, Professeur 

 a I'Universite de Kazan, Annales d. Sc. Nat., sixieme serie. Zool. T. 

 v., Nos. 3 a 5, June, 1877. 60 pp., plates xii — xv. 



