268 PROCEEDINGS OF THE ACADEMY OF [1898. 



1837. Apoma Beck, Index Moll., p. 89. For elongata Chemn. 

 (chemnitziana Fer.). Gray, 1847, and Morch, 1852, retain the 

 name for this species. 



1840. Cylindrella Pfeiffer, Archiv fur Naturg., p. 41. For 

 the following species : 



Gracilicollis Fer. [a Brachypodella] collaris Lam. [a Brachypo- 

 delict] antiperversa Desh. [a Brachypodella], subula Desh. [type of 

 the later group Mychostoma Alb.], perplicata Fer. [a Brachypo- 

 delict], chemnitziana Desh. [type species of the earlier group Apoma 

 Beck], elegans Pfr. [type of the later group Gongylostoma Alb.], 

 crispula Pfr. [a species of the later group Gongylostoma], f torticol- 

 lis (Oliv.) Lam. [=Clausilia of the section Bitorquata Bttg.]. 



Another Cylindrella, in Conidce, was proposed in 1840 by Swain- 

 son (Malacology, p. 311), and still again, for the group now gener- 

 ally known as Cylichna (t. c. p. 326. See Man. of Conch., XV, p. 

 287). It is now, so far as we know, impossible to decide whether 

 Pfeifler's group was published prior to Swainson's or vice versa. 

 Cossmann has proposed to substitute the term Distcectria (q. v.) for 

 Cylindrella Pfr. As Cylindrella is later than both Urocoptis and 

 Brachypodella, and the same name was used in the same year for 

 two other groups, we reject it from the nomenclature of this family. 



1840. Siphonostoma Swainson, Treatise ou Malacol., pp. 168, 

 333. For costata Gldg. and fasciata (Encycl. Meth., pi. 461, f. 17). 

 Name preoccupied by Voigt in Vermes, 1836 ; also used in Rotifera, 

 1832. 



1847. Brachypodisca Agassiz, Nomenclator Zool., Index Uni- 

 versalis, p. 51. An emendation, upon etymological grounds, of 

 Brachypodella Beck. 



1850. Thaumasia Albers, Die Heliceen, p. 207. Proposed for 

 decollata Nyst, liebmanni Pfr., gruneri Dkr., cylijidrus Chemn., san- 

 guinea Pfr., brevis Pfr., binneyana Pfr. 



The two first species belong to Eucalodium, the rest to the Jamai- 

 can and Haytien group of large Cylindrellas. Name preoccupied by 

 Perty in Arachnida, 1830. Spartina (q. v.) has been proposed as a 

 substitute, but it is superfluous, as the grouj) is a synonym of Uro- 

 coptis Beck, 1837. 



1850. Mychostoma Albers, Die Heliceen, p. 207. Proposed for 

 subula Fer., collaris Fer., gracilicollis Pfr., hanleyana Pfr., pallida 

 Guild., seminuda Adams. 



In the second edition of Die Heliceen, 1860, p. 37, von Martens 

 selects C. subula as type. 



