432 SUMMARY OF CURRENT RESEARCHES RELATING TO 



nerves and the ventre-- lateral skeleton of the tongue apparatus are like- 

 wise described for the first time. Regarding the phylogeny, it is stated 

 that the Trochidas and Turbinidse are doubtless nearly related to 

 Haliotis, which shows a similar, though not so marked asymmetry and 

 a like specialisation of the nervous system. Regarding the radula and 

 nervous system, Pleurotomaria is probably more primitive than Haliotis, 

 but with reference to the heart and branchial cavity the opposite is the 

 case. They are probably nearly related, and have very early arisen 

 independently from the same branch as the Prosobranchs, but not so 

 early as the Docoglossids and Fissurellids. The relations of the nervous 

 system and of the left kidney, suggest that the Monotocardia have not 

 arisen from the Trochidas and Haliotidae. 



Nematoblasts of Eolids.* — P. Abric gives some notes on the phases 

 in the stinging cells of Eolids. The nematocysts are grouped upon the 

 surface of the nematoblasts, and to these he gives the name of " agglu- 

 tinating cells." Later, they pass within the agglutinating cells, whose 

 reactions change ; they are now stainable with eosin, and are functional. 

 There appears to be a periodicity in the agglutinating cells, for in 

 Acanthopsoh they were found inactive at the end of spring. 



5. Lamellibranchiata. 



Gill of Pearl Oyster.f — W. A. Herdman calls attention to some 

 points of interest in the structure of the gill of the Ceylon pearl-oyster. 

 The first of these is the presence of extensive ciliated junctions (1) in 

 the median line between the inner gills of the two sides, and (2) laterally 

 between each outer gill and the mantle-lobe. The second is the presence 

 of somewhat extensive organic connections between the adjacent gill- 

 filaments of a plica at the level of the ciliated discs. In this character 

 of the interfilamentar junctions, as well as in that taken from the con- 

 nections of the gills with neighbouring parts, this member of the 

 Eleutherorhabda shows an approach to the Eulamellibranchiate con- 

 dition. 



Arthropoda. 

 a- Insecta. 



Synopsis of Families of Palaearctic Lepidoptera.f — K. von 

 Hormuzaki furnishes a useful analytical synopsis of the families of 

 Palaearctic Lepidoptera, for the most part in the form of diagnostic 

 tables, with illustrations of venation. 



Variation in Melitaea aurinia.§— V. P. Kitchin discusses the chief 

 tendencies to variation in this butterfly, as noted from a series of 110 

 Irish specimens. There are three principal variations in general appear- 

 ance, according as the chestnut, or the yellow, or the black colour 

 predominates. Variations on the upper wing, on the under wing, and 

 so on, are noted, as well as a few pathological aberrations. 



* Cnmptes Rendus, exxxix. (1904) pp. 611-13. 

 t Jnurn. Linn. Soc. (Zool.) xxix. (1905) pp. 226-9 (1 pi.).. 



X Analytisclie Ucbersicht der psilaarktischen Lepidopterenfaruilien, 8vo, Berlin 

 (1904) 68 pp., 45 figs. See Verb. Zool. Bot. Ges. AVien, lv. (1905) p. 128. 

 § Trans. Hertfordshire Nat. Hist. Soc., xii. (1905) pp. 165-7 (1 pi.). 



