ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 57 



and the iintliiferentiated germ cells found in the interior. In the 

 sporocyst some of the germ cells form another sporocyst generation ; 

 others remain as germ cells ; and some of them give rise to redias. 

 There is no parthenogenetic development of ova arising from somatic 

 . cells : there is a continuity of the germ cells, all descended from the 

 fertilized egg cell. This view has been corroborated in a recent paper 

 by Dolleus (11)19). J. A. T. 



Incertee Sedis. 



Larval Colonies of Pectinatella. — Stephen R. Williams [Proc. 

 Amer. Soc. Zool. in Anat. Record, 1920, 17, 3;>9). Balloon -shaped, 

 ciliated, larval colonies are set free from the gelatinous mass of the 

 adult, and after swimming about for a time, attach themselves by 

 mucous secretions to any convenient surface, especially one facing down- 

 wards. In laboratory conditions, through defective nutritive conditions, 

 the young colonies, which have on an average four polyps, degenerate 

 successively to three and two polyps, and then to one. When the rest 

 have gone the mucous attachment of the survivor elongates : the polyp 

 drops off and dies. J. A. T. 



EchiDoderma. 



Regeneration of Arms in Asterina g-ibbosa. — <iiusEPPK Zirpolo 

 [Boll. Soc. Nat. Napoli, 191.5, 28, 119-20). There is in this starfish a 

 ready regeneration of excised arms — even when all the five arms are 

 removed. There is a slight decrease in the regenerative capacity as the 

 number of arms to b ; regrown increases. The rapidity of the regenera- 

 tion varies, e.g. with size ; it is greater in spring than in winter (as 

 0"U;3 per day in spring to O'Ol per day in winter). J. A. T. 



Abnormalities in Arms of Asterina gibbosa. — Giuseppe Zirpolo 

 {Boll. Soc. Nat. Napoli, 191 (i. 29. ;5-16, 2 pis.). The occurrence of abnor- 

 malities in the arms of this starfish is frequent. . Thus there may be 

 four arms or six. The bifurcation of an arm is recorded. The number 

 of madreporic plates is variable. A supernumerary arm is usually 

 normal m structure. Fine photographs are given. J. A. T. 



Anomalous Specimens of Asterina gibbosa. — Giusepj'e Zirpolo 

 {Boll. Soc. Nat. Napoli, 1919, 32, 6o-7u). Records of three speci- 

 mens with four arms and four with six arms. Full details are given in 

 regard to the madreporic plate, the mouth plates, and the evidences 

 of reo-eneration. J. A. T. 



■"t>^ 



Anomalous Starfishes. — Giuseppe Zirpolo {Boll. Soc. Nat. Napoli, 

 l'.»16, 29, 49-58, 1 pi., 3 figs.). Records and figures of a specimen of 

 Chsetaster loiigipes with four arms, of another with one of the five arms 

 deeply bifurcate, and of a specimen of Hacelia attenaata with four very 

 regular and symmetrical arms, without anv trace of lesion or cicatrix. 



J. A. T. 



