94 Scientific Intelligence. 



Mi's. Brandegee furnishes interesting notes in regard to Dode- 

 catheon Meadia. She proposes to place the different forms pro- 

 visionally under four varietal heads. Mr. Brandegee sends a 

 short note about a forest of " Cardon," the Mexican name for two 

 species of Cereus, notably 0. Pringlei. Mr. Vaslit, speaking of 

 the genus Crossosma, is inclined to regard C. Bigelovii a depau- 

 perate form of O. Californicum. The journal contains a brief 

 review of recent literature, and also short but interesting reports 

 of meetings of the California Academy of Sciences, and of the 

 San Francisco Microscopical Society. 



It is a pleasure to welcome this carefully edited journal. We 

 hope that it will do for the Pacific coast what is so well done in 

 our nearer west by the Botanical Gazette and by the Bulletin of 

 the Torrey Botanical Club, on the Atlantic coast. g. l. g. 



3. Deep-sea Mollusks and the conditions under which they 

 exist ; by Wir. H. Dall. Presidential address before the Biolog- 

 ical Society of Washington. — The questions considered by Mr. 

 Dall bear on the characteristics and evolution of deep-sea life, 

 and have great interest, although, as Mr: Dall says, "the explor- 

 ation of the deep-sea faunas has only begun." The conclusion of 

 Tornoe that carbonic acid exists in the abyssal waters only in 

 combination is questioiied on the ground of the common occur- 

 rence of eroded shells. It may be questioned also on the ground 

 of animal respiration in the depths, and probably also on that of 

 decomposition, which would make free carbonic acid to be at 

 least temporarily present ; and considering that no plants exist 

 sufficient to use up the carbonic acid thus evolved the excess of 

 carbonic acid through the depths in some form must ever be on 

 the increase. Mr. Dall states that of the Mollusks the groups 

 that in shallow waters are phytophagous, live in the deeps chiefly 

 on foraminifera, which they swallow in immense quantities, and 

 he attributes to this the larger size of the intestine, the smaller 

 teeth and jaws, and other characteristics ; for there is very little 

 food in a given mass of them in proportion to that in algae. 

 The carnivorous mollusks are the prevailing kinds ; but the abys- 

 sal species, Mr. Dall states, may get all the food they want from 

 the pelagic life that descends at death from above, without prey- 

 ing on one another. The shells are not drilled, or otherwise 

 marked with evidence of attack by other mollusks. He gives facts 

 respecting the fishes of the bottom which show that they. live on 

 mollusks and make large shell heaps. According to Professor 

 Verrill, sea-urchins have been brought up with shells in their 

 stomachs, and star-fishes with sea-urchins inside ; so that depre- 

 dations are not wholly absent from the deep seas. Mr. Dall 

 observes that in deep-water mollusks the layer of aragonite of 

 the shells are thinner than in those of shallow water; the spines 

 of the Murices more delicate as if it were a character that was 

 fading out because unnecessary; the sculpturing is that which 

 strengthens in order to adapt to the pressure at the bottom ; the 

 operculum is generally horny and to a large extent absent ; the 



