22 



SCIENCE. 



[Vol. I., No. 1. 



able and competent au investigator as Prof. Biitschli. 

 It is one of tbe few works that may be fairly termed 

 indispensable to the microscopist and zoologist. (It 

 is stated from a competent private source that prob- 

 ably two years will be needed to complete the under- 

 taking.) c. s. M. [53 



History and distribution of the fresh-iwater 

 mussels. — Under this title Dr. R. E. C. Stearns 

 prints a suggestive paper, read before the California 

 academy of sciences, Nov. 20, 1882. The geographi- 

 cal distribution, geological history, and principal sub- 

 divisions of the Naiades are summarized, and the 

 species of the great basins and the Pacific slope sub- 

 sequently taken up in more detail. Anodonta Nut- 

 talliana, representing fom' nominal species, described 

 twenty-five years ago by Dr. Isaac Lea, from the 

 Wahlamet Eiver of Oregon, has been traced over an 

 immense area, including the drainage system of the 

 Coliunbia, the valley of California, the lakes of the 

 eastern slope of the Sierra Nevada, thence, either re- 

 cent or recently fossilized, across the desert to the 

 Wahsatch Mountains, northward to the southern 

 boundary of Idaho and Oregon, along the meridian 

 of 110° W., through part of Montana, tx) British Co- 

 lumbia, and southward to Fort Yuma. They are 

 found on the surface of the desert, and even, with 

 other still recent species, at a depth of at least fifty 

 feet below the surface. Some of the species have 

 been supposed to be extinct ; and in regard to Try- 

 onia, announced by Mr. Try on in 1S73 as found in the 

 living state in Utah by Wheeler's expedition (two 

 specimens), further confirmation seems desirable be- 

 fore it can be confidently claimed as still inhabiting 

 the region. The general uniformity of mollusk-fauna 

 over tlais region at one time is, however, sufficiently 

 evident. Dr. Stearns traces variations perpetuated 

 by natural selection during the changes brought about 

 in the region by important geological and climatic 

 changes ; the radiating distribution from higher alti- 

 tudes to lower, as the land rose and the waters re- 

 ceded; and the missing links in the chain of migration 

 arising from areal desiccation. He ascribes to the 

 period immediately preceding the glaciation of the 

 higher regions of this area, meteoi'ological conditions 

 more favorable to distribution of aquatic life than 

 any since obtaining there. The author then dis- 

 cusses the circumboreal distribution of foui' or five 

 species of Limnaea, Physa, etc., and of the fresh-water 

 pearl mussel (Margaritana margaritifera L. ), which 

 exhibits some remarkable characteristics in its range. 

 The latter is eaten by the McCloud-River Indians, 

 and by some Oregonian tribes. He concludes, with 

 Wetherby, that the earliest fresh-water forms were 

 lacustrine ; and the paper closes with references to 

 the comparative .antiquity of Unio and Anodonta, 

 and a list from Lea's synopsis of the number of 

 species of Naiades. — w. h. d. [54 



Studies of the Italian cretaceous fossils. — 

 Under the auspices of the Accademia dei lineei, 

 Professor G. Seguenza has just published a valuable 

 memoir on the middle cretaceous formation of south- 

 ern Italy. Already well known by his valuable con- 

 tributions to our Icnowledge of the tertiary strata of 

 the two Sicilies, and especially of Calabria, the pres- 

 ent publication can only add to his reputation. The 

 first part discusses the sufliciently simple geology of 

 this formation; tlie second is devoted to the fauna, 

 which is illustrated by sixteen quarto plates beauti- 

 fully drawn by the author. Of the 223 species de- 

 scribed in this work, 104 are supposed to be new, and 

 186 are mollusks. There are fish remains of two 



species, twelve echinbderms (of which nine belong 

 to the genus Hemiaster), and only four corals. Only 

 one brachiopod, a Discina, was collected. Of true 

 mollusks twenty are cephalopods, and fifteen gastro- 

 pods, leaving, as is evident, the majority lamelli- 

 branchiate. In fact, the characteristic feature of the 

 fauna is that it is chiefly composed of bivalve shells 

 belonging to the Yeneridae,Veniliidae,Crassatellidae, 

 Cardiidae, Arcidae, and the great heteromyarian 

 group of mussels and oysters. The new genus of 

 Corbulidae (?), Coquandia, is described from internal 

 casts (a condition very general among these fossils), 

 and appears to have somewhat resembled Eucharis 

 Eecl., but with the cardinal tooth in each valve pro- 

 digiously enlarged, flattened, straight, and set at 

 right angles to the margin. — w. H. D. [55 



North American Coleoptera. — A record of 

 coleopterology for 18S1 and 1882 was presented for 

 publication by F. G. Schaupp, The only foreign 

 descriptions of N. A. beetles were an Oedionychis 

 by Harold, a Triarthron by Schaufuss, a Cyma- 

 todera by Gorham, six Elateridae by Candfeze, and 

 some fifty Dytiscidae by Sharp. — (Brookl. ent. soc. ; 

 meeting Jan. 6.) [56 



Extension of the theory of mimicry in butter- 

 flies. — Mimicry of one butterfly by another widely 

 differing from it in structure was explained by Bates 

 as resulting from some special protection of the mim- 

 icked form, as, by distastefulness. Recently some 

 cases have occmred in which both genera involved 

 were similarly protected; and Fritz Miiller attempted 

 to explain this by showing how it was advantageous 

 for one species to resemble another which is more 

 abundant in individuals, although both may possess 

 qualities distasteful to those creatures which would 

 otherwise devoiu- them. Distant objects to this 

 extension of the theory; and adduces in support 

 Spalding's experiments upon young turkeys bred in 

 confinement, who showed instinctive alarm of sting- 

 bearing insects. Meldola here comes in, and takes 

 up the question of whether birds have an hereditary 

 distaste for nauseous insects, or learn of their nas- 

 tiness from sad experience. He claims the latter, 

 while Distant replies in favor of the former view. 

 The discussion partalves somewhat of a polemic char- 

 acter, and is rather barren considering our ignorance 

 of the facts in the case: when they disagree as to 

 which is the mimicking and which the mimicked 

 form, philosophizing is somewliat out of place; yet 

 some suggestions worthy of being Ivcpt in mind are 

 made by both parties. — (Arm. may. nat. hist., Dec, 

 18S2, and Jan., 18S3.) [57 



A carnivorous bee. — P. Parfitt captured on the 

 wing a male Halictus with its mouth full of insects; 

 viz., a fly, a larval homopteron, and several plant- 

 lice. — [Ent. monihl. mag., No. 223.) [58 



VEETEBRATES. 

 Origin of the hypoglossus and morphology of 

 the head. — Perhaps the most interesting and impor- 

 tant discovery in embryology made recently is that 

 of the nature of the hypoglossal nerve by Dr. August 

 Froriep. This investigator found, in ruminant em- 

 bryos, evidences of three distinct proto-vertebrae in 

 front of the first spinal or cervical nerve, and behind 

 the vagus. In front of each of these is a distinct 

 set of anterior nerve roots, which all unite into a 

 single trunk, — the hypoglossus. Over the posterior 

 of these sets of roots is a dorsal ganglion, which also 

 unites with the same nerve, and resembles the spinal 

 ganglia in position and shape, although smaller in 



