ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 651 



thinness of the Grundschiclit and its very constant and regular swell- 

 ings outside the nerve-sti'auds ; (7) the four bundles of longitudinal 

 muscles and the annular muscle in the fore-gut region of the proboscis ; 

 (8) the great strength and peculiar shape of the posterior end of the 

 proboscis sheath ; and (9) the position of the blood-vessels above the gut 

 in the anterior fore-gut region. The form described must be ranked as 

 representative of a new sub-family (Callinereae) of M'Intosh's Cari- 

 nellidae, that is, as very distinct from, though allied to, Carimna and 

 Carinella. 



Incertee Sedis, 



Structure of Polyzoa.* — Karl Schulz has examined the minute 

 structure of Membranipora membranacea and some other forms, with 

 special reference to the excretory organs. The author re-describes the 

 excretory apparatus in Pedicelliria, giving the histology in detail, and 

 emphasising the homology with the protonephridia of Annelids. In 

 Phytactolaemata among Ectoproctous forms, the dilated unpaired region 

 of the forked canal contains excretory cells, in which the products are 

 stored throughout life. The canal cannot be regarded as the homologue 

 of the segmental organs of Annelids. In GyinnolaBmata there is no 

 definite excretory organ, the intertentacular organ is merely the oviduct. 

 In Membranipora, the excretory function is performed by the free mesen- 

 chyme cells of the body-cavity, probably also by the cells of the meso- 

 dermic epithelium of the tentacles. 



Rotatoria. 



North American Rotatoria.! — Prof. H. S. Jennings gives a synopsis 

 with diagnostic tables of North American Rotifers (240 species) which 

 are much the same as those of Europe. The system employed by 

 Hudson and Gosse is followed, but with some reservations ; and certain 

 divisions are introduced which are not given in the famous monograph, 

 such as the general division into Digonata (with two ovaries) and Mono- 

 gonata (with one ovary). Certain families, e.g. Apsilidse, Plcesomadaa, 

 Gastropodidas, and Anapodidae, are added to those given by Hudson and 

 Gosse. 



Echinoderma. 



Natural History of Starfish.! — Dr. A. D. Mead has studied Asterias 

 forbesii and A. vulgaris, and discusses their distribution, locomotor 

 powers, migration, feeding habits, reproduction, development, and re- 

 generation. 



A common rate of movement is 6 in. per minute, but there is no 

 evidence that they travel far. Especially when young they are very 

 voracious, — in six days one ate 50 clams. They feed on oysters, mussels, 

 clams, oyster-drills, barnacles, worms, or even smaller starfish. The 

 answer which Schiemenz gave to the question, " How does a starfish open 

 an oyster ? " is confirmed. Although some ripe starfishes may be found 

 almost at any time, there is in Narragansett Bay a short spawning 

 season beginning about the second week in June and continuing for two 



* Arch. Naturgesch., lxvii. (1901) pp. 115-44 (1 pi.). 



t Amer. Nat., xxxv. (1901) pp. 724-77 (9 pis.). 



I Bull. U.S. Fish Commission for 1899 (published 1900). pp. 203-24 (4 pis.). 



