NOVKMBEE 30, 1900.] 



SCIENCE. 



823 



aB to which body of sea water it was origi- 

 nally connected with. Dr. W. Dybowski 

 contends that the ' stammform ' of one of 

 the Baikal sponges {Lubomirskia baicalensis") 

 .is an inhabitant of Bering Sea. Hoernes 

 has regarded the fauna of the lake as anal- 

 ogous to that of the Sarmatic beds of South- 

 ern Europe, but this analogy is hardly 

 greater than it bears to various other late 

 Tertiary lake-beds, including those of our 

 Great Basin. In the September number 

 of the Nachriehtsblatt der deutschen Malaho- 

 zoologisehen Gesellsehaft, Dybowski announces 

 the discovery of a Nudibranch (Ancylodoris 

 baicaleiisis, Dyb. ) and the presence of nu- 

 merous Trochophora larvae in April, in the 

 lake. These being strictly marine animals, 

 never before reported from fresh water, the 

 evidence as to the lake's origin seems con- 

 clusive, and its character as a ' relicten- see ' 

 positively established. 



Mr. Henry Hemphill has recently for- 

 warded to the Nationa,! Museum a photo- 

 graph of a six-valved specimen of Ischnochi- 

 ton obtained by him at San Diego, California. 

 Seven-valved specimens (the normal num- 

 ber being eight) are known to be preserved 

 in the British Museum and the Academy of 

 Natural Sciences at Philadelphia ; and now 

 Mr. E. E. Sykes figures in the Journal of 

 Malacology (VII., p. 164) a three-valved 

 specimen of Ischnochiton contractus Eeeve, 

 from South Australia. The rarity of these 

 abnormal individuals makes the discovery 

 most interesting. In another note Mr. 

 Sykes records the presence in the fauna of 

 Natal of a species of the genus Crypfoplax, 

 pieviously supposed to be confined to the 

 Indo-Pacific and Australian provinces. 



Dr. George W. Taylor, of Nanaimo, has 

 added a new genus to the fauna of the Pa- 

 cific coast in the shape of an undescribed 

 species of Phyllaplysia (P. Taylori) which 

 was found near Nanaimo on floating sea- 

 weed. The animal is of a clear lemon-yel- 

 low, about an inch in length and with a 



nearly smooth surface. The genus has 

 heretofore been known only from the coasts 

 of France and the Adriatic. 



Pelseneer has been pursuing researches 

 on the various mollusks believed to exhibit 

 archaic features.* He devotes attention 

 chiefly to the Chitonacea, the Docoglossa, 

 Rhipidoglossa and Solenoconcha. His con- 

 clusions do not include any remarkable 

 novelties, but afford in many cases addi- 

 tional confirmation of opinions long held 

 or occasionally expressed by macologists. 

 Thus he considers the metamerism of chi- 

 tons to be a secondary, not primitive, con- 

 dition ; recognizes the features of the Doco- 

 glossa limpets which are analogous to those 

 of the Amphineur a, confirms the unlikeness 

 of Scissurella to Pleurotomaria and the asym- 

 metry of the epipodial processes in the 

 Trochidse. Some interesting new facts are 

 recorded among the Pyramidellidse ; Odos- 

 tomia was found to be hermaphrodite, but 

 otherwise related to ordinary Pectini- 

 branchs. The Scaphopods he considers to 

 have distinct relations with the Rhipido- 

 glossate gastropods, but one of the charac- 

 ters, the opening of the genital duct into the 

 right nephridium, has already been shown 

 to be fallacious by H. Fischer, the error be- 

 ing due to the torsion in the embryo. It is 

 probable that this supposed relation will 

 not be accepted by students of the group. 

 In regard to the nephridia of both Doco- 

 glossate and Ehipidoglossate limpets, Pro- 

 fessor Pelseneer is at variance with Er- 

 langer; but in another contested hypothesis, 

 the relation of the Placophora and Aplaco- 

 phora, in which he differs from Thiele by 

 regarding the groups as related, we believe 

 Pelseneer to be right. At any rate, whether 

 all details be confirmed by future research 

 or not, the present paper contains much 

 which will prove welcome to students of the 

 Mollusks. 



*Mem. Acad. Boy. des Sci. de Belgique, LVII. 1899. 

 Pp. 113. 



