644 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tocardia has been derived principally from the right kidney of the 

 Diotocardia. These are the true excretory organs, the left kidney or 

 papillary sac of Trochus and its allies being more of the nature of a 

 lymphatic gland. The nephridial gland of the Monotocardia possesses 

 similar functions, and so, from a physiological point of view, can more 

 easily be homologised with the papillary sac of Trochus. 



Muscular Fibres in Heart of Nassa reticulata.* — M. Mader 

 shows that the fibres in this Gastropod are in a state of differentiation 

 intermediate between the unstriped fibre and the fibre of simple striation, 

 described by Vigier in Anodonta ; it is a transition-type towards the 

 complex striated fibre of Arthropods and Vertebrates. 



Phylogeny of Fusus and its Allies.f — Amadeus W. Grabau dis- 

 cusses the genetic relationships of Fusus and its allies. Starting from 

 Eocene species of Fusus, he describes more than half-a-dozen series of 

 species, and indicates their probable phylogeny. He also deals with 

 species of Fusoid shells generally referred to Fusus— the genus Aptyxis, 

 various Eocene species, the new genus Heilprinia, and the genus Euthrio- 

 fusus. Then follows a discussion of phylogerontic Fusida3— the genus 

 Ctjrtulus and the Eocene Clavilithoids. A study of the geographical 

 distribution closes the memoir. 



Mendelian Phenomena in Gastropods4 — G. Contagne maintains 

 that Mendelian or "polytazic " phenomena may be recognised in various 

 Gastropods in natural conditions — e.g. Cyclostoma elegans, ValJonia 

 pukheila, Ccelistde hispanica, Helix planospira, H. piscina, H.nemoralis. 



Chitons from the Pacific.§ — Curt von "Wissel reports on collections 

 of Chitons made by Schauinsland and Thilenius in the Pacific, nineteen 

 forms in all, belonging to the genera Ischnochiton, Mopalia, Cluetophura, 

 Plaxiphvra, Acanthochites, Cryptoconchus, Katharina, Chiton, Onitho- 

 chiton. The author has been able to work out the anatomy in some 

 detail. An appendix describes three species of Oncidiella from New 

 Zealand. 



Anatomy of Lottia gigantea.|| — W. K. Fisher has investigated the 

 organisation of the Acmajidse as exhibited in this species. The follow- 

 ing are some of the most notable points elucidated. The Acmseidae 

 possess a larval nautiloid shell. The lips are armed with tiny teeth. 

 The nephridia are very unequal in size, the left being a tiny sac on the 

 left side of the rectum. Both are in communication with the peri- 

 cardium by long canals, which are really diverticula of the pericardium. 

 The circulation is for the most part closed. Sinuses, however, collect 

 the blood in the foot, and there are also open lacunas of minute size in 

 the liver. The arterial system is extensive. Over the nephridia there 

 is present a highly developed vein-net. The mantle discharges its 

 blood directly into the auricle. The innervation of the mantle is 



* Comptes Rendus, cxxxviii. (1904) p. 1537. 



t Smithsonian Misc. Collections, xliv. (1904) pp. 1-1 GO (18 pis. and 22 figs.). 



\ Comptes Rendus, cxxxviii. (1904) pp. 1521-3. 



§ Zool. Jahrb., xx. (1904) pp. 591-676 (5 pis. and 10 figs.). 



|| Tom. cit., pp. 1-66 (4. pis.) 



