66 SUMMARY OF CURRENT RESEARCHES RELATING TO 



specific and zonal determination might be placed on a permanent and 

 scientific footing. 



The result of the paper is to show, from the beginning of the low-zonal 

 series to the beginning of the high-zonal series, an unbroken continuity 

 in the evolution of Micraster ; " so that as we mount up, zone by zone, 

 fresh features are added to the test, simply owing to the progressive- 

 elaboration of the epistroma ; and in each zone the special features of 

 the test are so marked that one can tell by their aid from what zone a 

 Micraster is derived." 



Lr. Eowe divides the genus into four groups : — of M. cor-bovis, of 

 M. leskei, of M. prsecursor, and of M. cor-anguinum auctorum. " True 

 species, and even prominent varietal types, are rare, and passage-forms- 

 and trivial variants are the rule. Nothing but a group will embrace 

 them all, and give to each series its correlative value." Unless the 

 passage-forms and mutations be united into a group which will admit of 

 the zoological continuity being exemplified, and the zonal peculiarities- 

 noted, a species must be made for each variation, and that in each zone. 

 " The one plan is sufficient for all purposes of nomenclature, and at the 

 same time it marks the evolution of the genus, zone by zone ; the other 

 is mere ticketing, and meaningless ticketing to boot." 



Revision of Genera and Species of Starfishes.* — Mr. A. E. Verrill 

 describes various collections of starfishes, made by the ' Blake,' the 

 ' Albatross,' and other expeditions, giving descriptions of new species,, 

 and a revision of old species and genera. The paper is illustrated by 

 numerous figures of structural points. 



Zanzibar Echinoderms.f — Prof. H. Ludwig gives an account of 

 a collection from the Zanzibar region, and a list of the known forms- 

 (127 in all, as compared with 77 in 1869). His list includes 4 crinoids, 

 29 asteroids, 21 ophiuroids, 36 echinoids, and 37 holothuroids. 



New Holothurians.J — E. Herouard publishes a revision of the 

 Elpidiinse, with descriptions of some new species based on specimens 

 taken by the ' Princess Alice.' His revision of the sub-family takes 

 into account four structural characters which vary in concert. These- 

 are : — the orientation of the tentacular disc, the distribution of the dorsal 

 papillae, the position of the ventral ambulacral tube-feet, the degree of 

 flattening of the body. The variations of these structures are briefly 

 considered, and the results embodied in a synoptic table of the known 

 genera with lists of species. 



Ccelentera. 



New Hydroid from Long Island Sound.§ — Mr. C. F. Sigerfoos de- 

 scribes Stylactis hooperi sp. n., growing on the shells of living specimens 

 of llyanassa obsoleta, as one of the most beautiful and graceful of 

 Hydroids. The delicacy of the individuals seems correlated with the 

 protection afforded through association with the mollusc and the habitat 

 in a locality free from high winds. 



The diagnosis runs : — Hydrocaulus absent ; hydrorhiza a network of 



* Trans. Connecticut Acad., x. (1899) pp. 145-234 (8 pis.). 

 t Abh. Senckenberg. Nat. Ges., xxi. (1899) pp. 537-63. 

 t Bull. Soc. Zool. FraDce, xxiv. (1899) pp. 170-5 (4 figs.). 

 § Amer. Nat., xxxiii. (1899) pp. 801-7 (5 figs.). 



