202 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Copepods parasitic on Alcyonarians.* — Antonio de Zulueta de- 

 scribes some new species of Lamippe, and discusses the constitution of 

 the characteristic buccal apparatus and of the furca. On the latter 

 there are interesting aciculi, which alter in length and often bear a 

 refringent globule. The author compares this peculiar kind of aciculus 

 to the axis in the pseudopod of a Heliozoon. One of the interesting 

 facts about the species of Lamippe is that each of the eleven Alcyonarians 

 examined had its own particular parasite. 



Annulata. 



Internal Fertilization in Pareudrilus.t — Luijji Cognetti de Martiis 

 finds evidence that the receptaculum seminis in Pareudrilus pallidas is 

 not merely a storage-house for spermatophores, but is adapted to 

 facilitate internal fertilization by migration of the spermatozoa. 



Neurochords of Criodrilus.J — Josef Honig finds three neurocbords 

 in the dorsal part of the ventral nerve-cord of this Oligochset, ex- 

 tending from the hindmost ganglion to the sub-oesophageal. They 

 appear to arise from nerve-cells in the last ganglion. In all parts of 

 the body they are connected with ganglion-cells, in a perfectly definite 

 way, which is described. Each lateral twig of the neurochord contains 

 a twig of the neurofibril bundle of the giant fibres. The envelope of the 

 neurochord and of its lateral twig contains a variety of glia-cells. 



Development of Criodrilus lacuum.§— Franz Staff finds that the 

 cell lineage in this type is like that described by Wilson, Bergh, and 

 Yejdovsky in LumbricidEe. Between the mesoderm band and the 

 ectoderm, embedded in the latter, there are on each side four pairs of 

 cell-rows, which spring from posterior pole-cells. 



The nephridia develop from the retro-peritoneal cell-row which lies 

 laterally to the "primitive muscle-fibres." The row falls into seg- 

 mentary arranged groups of cells which protrude into the ccelom and 

 are enveloped in peritoneum. 



The upper lip of the funnel arises from a large pras-septal cell 

 (" funnel-cell " of various authors), which divides repeatedly. The 

 lumen of the funnel arises by a folding of the septal wall between the 

 upper lip and the first cells of the loop. 



Studies on Arenicolidae. — J. H. Ash worth || reports on the Areni- 

 colidas in the Berlin Museum, which include Arenicola marina (Linnaeus) 

 = A. piscatorum Lamarck, A. claparedii Levinsen, A. assimilis Ehlers, 

 A. assimilis var. affinis Ashworth, A. grubii Claparede, and A. ecaudata 

 Johnston. 



The author reports also If on the North and South American species, 

 which include the first three mentioned above, along with the gigantic 

 A. cristata Stimpson and A. glacialis Murdoch. Of the last-named a 



* Arch. Zool. Exper., vi. (1910) pp. 137-48 (17 figs.). 

 t Atti Accad. Sci. Torino, xlv. (1910) pp. 737-50 (1 pi.). 

 X Arb. Zool. Inst. Univ. Wien, xviii. (1910) pp. 257-82 (1 pi. and 1 fig.). 

 § Torn, cit., pp. 227-56 (2 pis.). 

 !| MT. Zool. Mus. Berlin, iv. (1910) pp. 317-54. 

 \ Proc. U.S. Nat. Mus., xxx. (1910) pp. 1-32. 



