746 SUMMARY OF CIJEEENT KESEAECHES RELATING TO 



plates " of which Professor Verrill speaks exhibit a striking advance 

 on what has been seen in Solaster or in Crossaster ; there are now 

 two sets, one dorso-marginal and one ventro-marginal. The writer 

 submits that this gradation points to the presence of three distinct 

 though allied genera. A new species C. neptuni, from the coast of 

 Ecuador, is described. 



Coelenterata. 



Origin of the Ovum of the Hydroida.* — M. A. de Varenne, who 

 has examined Campanularia flexuosa, Plumularia echinata, and Ser- 

 tularia piimila at Eoscoff, finds that the ovum is not developed in 

 the gonophore, but in the stem of the hydroid. Examining a form, 

 Gonothjjrcea Lovem, in which the gonophore becomes an attached 

 Medusa, he again noticed that the ovum arose from the endodermal 

 cells of the stem, while the same observation was made for the 

 eggs of Podocoryne carnea, and Obelia geniculata, in which the 

 gonophores become free-swimming Medusas. The author insists that 

 the ova are not developed within the gonophore, that every stage can 

 be made out between them and the ordinary endodermal cell ; and he 

 comes to the more general conclusion that neither the buds, the 

 gonojihores, or the Medusae can be rightly looked upon as sexual 

 individuals. 



American Acalephae.t — Mr. J. W. Fewkes describes as new 

 Lafoea elegans, Campanularia insignis, Sertularella formosa, and Plumu- 

 laria caulitheca, which, unlike other species of the genus, has a large 

 nematophore, not free as the others of the same species, which arises 

 from the stem upon the upper side of a projection of the hydrocaulus 

 from which the pinna springs ; also Aglaoplienia insignis, A. gracillima, 

 A. mimita, A. crenata, and A. robusta. Aglaoplieniopjsis is a new genus 

 which resembles somewhat MacrorJiyncJiia, but does not have the 

 pinnfe carrying gonophores ; like Halicomaria, it has a nematophore 

 modified into a long jointed stalk, but, contrary to what happens in 

 that genus, these appendages are not confined to the proximal 

 hydrotheca (A. hirsuta). Antennopsis ramosa is a new species. The 

 new genus Callicarpa (C. gracilis and C. compressa^ difi'ers from all 

 known genera of Hydroids in having a gonosome which closely 

 resembles a spike of wheat, and springs by a short peduncle from the 

 main stem. The new genus Pleurocarpa (P. ramosa) has likewise a 

 peculiar gonosome, which is formed from the proximal portion of a 

 branch, while the distal end of the same retains the true characters of 

 the branch, and bears pinnae. 



Jelly-fishes of Narragansett Bay.| — Mr. J. W. Fewkes points 

 out that a portion of the base of the tentacle of Sarsia mirabilis is 

 specialized into a spherical body, which projects downwards as the 

 jelly-fish swims in the water, hanging below the margin of the bell. 

 The cellular bodies in the wall of this enlargement " indistinctly 

 resemble lasso-cells," but appear to have some special function. 



* Comptes Rendus, xciii. (1881) pp. 345-7. 



t Bull. ]\Ius. Coiiip. Zool., viii. (1881) pp. 127-39 (4 pis.). 



X Ibid., pp. i41-7G (10 pis.). 



