728 SUMMARY OF CURRENT RESEARCHES RELATING TO 



there is a precisely parallel total absorption of the differentiated sex- 

 elements which remain unused after the breeding season. In many 

 animals a similar phagocytic absorption has been observed, but it has a 

 remarkable intensity in Echinocardium cordatum, which is also a very 

 convenient subject for studying the process. 



Development of the Biserial Arm in Certain Crinoids.* — A. 

 W. Grabau finds that new arm-plates introduced at the tip of the grow- 

 ing arm are uniserial. The apical plates, at least in the less specialised 

 biserial species, are rectangular, and change with further growth to 

 wedge-shaped and later to biseriality. This is not primarily an old age 

 character, since this condition is found in the apical arm-plates of young 

 crinoids. 



List of Irish Echinoderms.! — A. R. Nichols gives a list of Irish 

 Echinoderms with their localities, together with their general dis- 

 tribution. He notes as peculiar to Irish shallow waters two doubtful 

 species of Gucumaria, G. andrewsi and G. saxicola, and five deep-water 

 forms, Holothuria aspersa, Astropecten sphenoplax, Pentagonaster greeni, 

 Hymenaster giganteus and Cidaris gracilis. 



Echinoderms of East Finmark.J — Canon A. M. Norman gives a 

 list of these, briefly indicating their localities and authorities. No new 

 species are recorded. 



Coelentera. 



Commensalism between Sea-Anemone and Crab.§ — Otto Burger 

 notes that the common Pacific sea-anemone — Antholoba reticulata — has 

 a distribution area which overlaps that of the crab, Hepatus chilensis, in 

 the Bay of Coquimbo. In this area the sea-anemone is usually found 

 seated on the cephalothorax of the crab ; in other regions it does not 

 seem to have discovered any suitable bearer. Out of sixty crabs cap- 

 tured in Coquimbo, only four were without the anemone, and some had 

 two or more. Burger was twice successful in observing a sea-anemone 

 clambering on to the crab by slow stages, after it had been separated 

 from it for four days. The association is not fortuitous, and the 

 anemone takes the initiative in establishing it. Probably the benefit is 

 on its side only. 



Revision of the Nephthyidse.|| — W. Kiikenthal has published a 

 welcome revision of one of the most difficult Alcyonarian families, 

 the Nephthyidae, which includes eight genera — Lithophytum, Eunephthya, 

 Gapnella, Lemnalia, Scleronephthya, Nephthya, Spongodes, and a new 

 genus Neospongodes. A number of new species, especially of Nephthya, 

 are described. 



Occurrence of Monograptus in New South Wales.1T — T. S. Hall 

 corroborates J. Mitchell's record of the occurrence of Graptolites in the 



* Amer. Journ. Sci.. xvi. (1903) pp. 289-300 (11 figs.), 

 t Proc. Royal Irish Acad., xxiv. sec. B, part 3, pp. 231-67. 

 I Op. cit, xii. series 7, No. 70, pp. 406-17. 

 § Biol. Centralbl.,xxiii. (1903) pp. 67S-9. 

 i| Zool. Jahrb., xix. Heft. i. (1903) pp. 99-172 (3 pis.). 

 1 Proc. Linn. SocN.S.W., xxvii. (1902, published 1903) pp. 654-5 (1 fig.). 



