MICRALYMMA MARINUM (STROEM) IN NORTH 
AMERICA: BIOLOGICAL NOTES AND NEW 
DISTRIBUTIONAL RECORDS 
(COLEOPTERA: STAPHYLINIDAE)* 
By Margaret K. Thayer 
Museum of Comparative Zoology and 
Department of Organismic and Evolutionary Biology 
Harvard University, Cambridge, Massachusetts 02138 
Micralymma marinum (Stroem) is an amphi-Atlantic intertidal 
beetle whose wide distribution in the Old World is fairly well known 
(Lindroth 1931, 1957; Steel 1958), but its range in North America 
has not been well documented. LeConte (1863) described M. stimp- 
sonii from the “coast of Maine.” Lindroth (1931:206) regarded this 
species as merely a variety of M. marinum and Steel (loc. cit.) listed 
it as a synonym of the latter. This synonymy has not been listed in 
North American catalogues (Leng et al. 1933-1948, Moore and 
Legner 1975) or Arnett’s manual (1968). After comparing the uni- 
que type of M. stimpsonii (a female) with the North American 
specimens listed below, a specimen from Iceland identified by Lin- 
droth (also a female), and the illustrations (including aedeagus) pro- 
vided by Steel (1958), I agree that M. stimpsonii is synonymous with 
M. marinum. The vague type locality of M. stimpsonii , further 
south than any European records, has been the only record of the 
species from the United States, and although Lindroth (1957: fig. 
32) mapped records from northwest, south, and southeast New- 
foundland and Steel (loc. cit.) mentioned seeing specimens from 
there, neither provided specific locality data. Since it appears that 
no specific New World locality records have been published for M. 
marinum , it seems worth presenting some recently acquired data, 
particularly since one recent record extends the known range of the 
species south to Massachusetts at latitude 42°25'N. Two specimens 
collected by Palmen whose records were apparently included on 
Lindroth’s map (1957: fig. 32) are among those listed. 
Unless noted otherwise (“no ecol. data”), all of the specimens 
listed were collected on rocks or in rock crevices in the intertidal 
* Manuscript received hy the editor October 2. 1984 
49 
