CURRENT LITERATURE 153 



Dr. Stempell proposes the name F. rosaceus, the former being preoccupied by 

 Sowerby (i). — W. E. C. 



Stempell, W. — Zur Anatomie von Solemya togata, Poli. Zool. Jahrb. (Abth. f. 

 Morph.), 1899, Bd. xiii, pp. 89 — 170, T. 8—10. 



Supplementing his valuable researches upon the XucuUda:, Dr. Stempell has 

 given a very complete account of the anatomy of Solemya togata, Poli. The work 

 was undertaken with the object of determining more exactly the value of the order 

 Protobranchiata, constituted by Pelseneer in 1S89 for the SoJemyidce and Xucididce. 

 In accepting this order the author gives an emended definition, eliminating many 

 of the characters given by Pelseneer as not being essentially characteristic. The 

 two families are carefelly compared and the difterences between them stated. The 

 Solcmyidce are regarded as the more specialised, a conclusion previously arrived at 

 by Pelseneer, but Dr. Stempell differs from that author in not agreeing that the 

 Sohinyidce have been derived from the XucuUdcc, he concludes, that in many points 

 the former show greater simplicity due probably to the nature of their environment, 

 and that both have been derived from a common ancestor possessing primitive 

 characters, many of which have been retained. — \V. E. C. 



Stearns, R. E. C. — List of shells collected ♦ in Heron and Eagle Lakes, Min- 

 nesota, with notes. Proc. U. S. Nat. Mus., 1899, vol. xxii, pp. 135— 138. 



Records 18 species and numerous varieties. 



Stearns, R. E. C. — Description of a new variety of Haliolis, from California. 

 Ibid., pp. 139 — 142. 



H. fuhjcns, Phil. v. nov. icalaUensis. Differs from the type in its more elongate 

 and flattened form, its constantly finer, spiral threading, and its paler nacre. 



Kelly, H. M.— A Statistical Study of the Parasites of the Unionidce. Bull. 

 Illinois State Lab. N. H., 1899, vol. v. pp. 399—418. 



Professor Kelly records some very interesting observations upon the parasites 

 found infesting 44 species of American Unionidce. The commonest parasite is 

 As]}idogast(r conchicola, v. Baer, others mentioned are Catylaspsis iiisigiiis, Leidy, 

 4 species of Distomidcc, Bucephalus polymorphus, v. Baer, and two other cercaria, 

 various species of Atax, 2 species of Infusoria, and an oligochrete worm. The 

 largest number of dift'erent parasites in any one species was found to be 7, many had 

 6, 5, or 4. Six very carefully prepared tables are given. As a result of his studies 

 the author arrives at the following conclusions: '"The host species seem to exhibit 

 unlike capacities for infestation, both as to the number of individuals and the kinds 

 of parasttes present. It appears that the differences shown are attributable only in 

 a minor degree to the age and size of the host, the size of the stream, and the 

 density of the unionid population. They are not sufficiently accounted for by the 

 seasonal variation, — which is shown to exist to some degree at least in the case of 

 certain parasites, — nor by the very slight difference in general structure between the 

 various host species. The evidence therefore seems to indicate that the capacity 

 for infestation in each host species is to a large extent a specific characteristic." — 



\V. E. C. 



Knig'ht, G. A. F. — The Etymology of the names Azeca and Assiminea of Leach. 

 Journ. Conch., 1900, vol. ix, pp. 271 — 76. 



This is an interesting and useful paper and throws much light upon many of the 

 generic terms used by Leach, whose derivation has hitherto been doubtful. The 

 two in the title of this paper were regarded in 1842, by a committee of the British 

 Association, as being "without any derivation or meaning whatever," and even 

 Jeffreys says of Assiminea, "a ridiculous name." Mr. Knight enumerates the 

 following names, and gives their probable derivation : Thracia, Mysia, Bithi *' 

 Thyatira, Lasaxi, Dipsas, Pharus, Magdala, Barnca, Azor, Macoma, Oronthl 



