352 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Development of Species of Upogebia. — Gladys E. Webb {.Town. 

 Marine Biol. Association, 1910, 12, 81-134, 12 pis.). A careful, well- 

 illustrated account of the larval and post-larval stages of two Thalas- 

 sinidse, Upogehia deltura Leach and U. stellata (Mont.). The larvfe were 

 taken from the tow-nets, and their further development was observed in 

 the laboratory. The adults live in long burrows beneath the mud. 

 Several features of special interest in the development are noted as 

 possibly indicating that sex differentiation commences at a very early 

 period — perhaps from the very beginning of the larval development — 

 and that the two sexes differ in the number of moults they undergo 

 during the larval life. J. A. T. 



Genus Phreatogammarus. — Chas. Chilton {Journ. Zool. Research, 

 1918, 3, 81-6, 10 figs.). This genus was established by Stebbing in 

 1899, the type species being P.fragilis (Chilton), a blind species found 

 in wells. It is near to Gammarus, but the first joint of the mandibular 

 palp is not very short, the first and second pergeopods are shorter than 

 the third, the fifth is the longest, the third uropod is long, with two one- 

 jointed cylindrical rami. Two New Zealand species have been added, 

 P. propinquus Chilton from 2800 feet above sea level, and P. helmsii 

 sp. n.j from the mouths of streams near high-water mark. J. A. T. 



Annulata. 



Fossil Polychsets. — Frederick Chapman {Proc. Roy. Soc. Victoria, 

 1919, 31, 315-24, 2 pis.). Some Victorian Silurian fossils, often called 

 *' fucoids," turn out to be well-preserved gilt-plumes (prostomial appen- 

 dages), referable to the genus Trachyderma Phillips. They have some 

 resemblance to the gilt-plumes of DasychoJie and other Sabelliform 

 Polychffits, bnt a new family Trachydermidse is probably required. A 

 description is also given of Cormdites younji sp. n., represented by 

 trumpet- shaped tubes. The genus Cormdites has sometimes been 

 referred to Pteropods, bat Chapman holds that the evidence for the 

 Annelid character of Cornulites is convincing. G. R. Vine has shown 

 that the microscopic structure of the conical shell is identical in many 

 points with that of some living Serpulidse. He suggests that Pterocomis 

 (or Nereitopsis) from Cornwall is also a tubicolous Annelid. J. A. T. 



Early Development of Protula meilhaci. — A. Soulier {Arch. 

 Zool. Exper., 1919, 57, Notes et Revue, No. 1, 14-20, 4 figs.). An 

 account is given of what follows the 32-cell stage in the development of 

 this Annelid. There is an occurrence of the cellular arrangements 

 which Wilson has called the rosette and cross. These also occur in 

 Polyclads and Molluscs. In Nereis, Capitella and Protida the rosette 

 and cross are formed from the same elements and lead to similar 

 results. The cells of the rosette in Protida form the ciliated tuft, and 

 those of the cross form the primordium of the cerebral ganglia. 



J. A. T. 



