THE NAUTILUS. 141 



SOME CRITICISMS ON DR. F. HAAS' MONOGRAPH OF THE UNIONID-E. 



BY ].. S. FKIERSON. 



The well known Monograph of Unionidse of H. C. Kuster is now 

 being continued by Dr. F. Haas, and of) plates of fine figures have 

 been received. Dr. Hans is a prolific maker of new genera, he hav- 

 ing added already 14 new ones to the tremendous total, although 

 three plates only deal with the groups of eastern Asia. The new 

 genera are fully as heterogeneous as are many of those of his 

 predecessors. 



Shells so close as Nodularia jourdyi Morelet and douglasia Greg, 

 are widely separated, and yet such diverse material as jourdyi and 

 asperula Lea are placed together. The Physunio crossei and Nodu- 

 laria rusticus, by Simpson's classification, are placed by Dr. Haas in 

 the same genus, etc., etc. 



The specific determinations are equally open to criticism. A few 

 of the more striking are as follows : On plate 33, figs. 7, 8 and 9 are 

 given as P. micropterus Morelet, and Unio pulcher Tapperone-Canefri 

 is given as a synonym. While these species bear considerable resem- 

 blance in their external facies, yet they are so diverse as to warrant 

 their being placed in different genera, as was properly done by Mr. 

 C. T. Simpson. P. micropterus has very small but well-defined beak 

 cavities, while pulcher has none. L. pulcher has a row of several dorsal 

 muscle scars, while micropterus shows none (i. e., hidden beneath 

 the interdention). More especially, micropterus has a " third mus. 

 cle scar " over the anterior adductor, not shown by pulcher, and the 

 latter has the anterior adductor and protractor scars widely separate 

 (which is shown in Haas' figure), while in micropterus they are con- 

 fluent. Other differences might be noted, the whole forcing us to 

 place micropterus in Physunio, while the pulcher belongs to Lamel- 

 lidens, as Mr. C. T. Simpson properly placed them. 



Figures 11 and 12, plate 31 are said to be figures of the Harmandia 

 somboriensis Rochebrune. If these figures are from authentic 

 specimens, then Harmandia must lose its place as a genus, for figures 

 11 and 12, are young ffyria, from South America. Even more 

 singular is the treatment of the genus Trapezoideus, on plates 32 and 

 33. It is impossible that the sundry figures given as Trapezoideus 



