100 U.S. NATIONAL MUSEUM BULLETIN 2 78 



Pseudaeginella Mayer, 1890 



Flagellum of antenna 2 biarticulate, swimming setae absent; man- 

 dible with 3-segmented palp, setal formula for terminal article 1-3-1, 

 molar?; outer lobe of maxUliped larger than inner lobe; gills on 

 pereonites 3 and 4; pereopods 3 and 4 absent, pereopod 5, 6-segmented; 

 abdomen of male and female without appendages. 



Type-species: Aeginella tristanensis Stebbing, 1888 (by monotypy). 



Pseudaeginella antiguae Barnard, 1932 



Figure 51 



Pseudaeginella tristanensis [not Stebbing]. — Stebbing, 1895, p. 402. — Mayer, 



1903, p. 59. 

 Pseudaeginella antiguae Barnard, 1932, p. 301. 



Remarks. — This species was described by Mayer (1903) and Steb- 

 bing (1895) as P. tristanensis from specimens collected in Antigua, 

 West Indies. Barnard later changed the name of these specimens to 

 P. antiguae with the following comment: 



In view of these specimens it becomes very unlikely that the sepcimens (Stebbing 

 says one; Mayer says two) from Antigua are conspecific. The female according 

 to Mayer (1903, p. 59) has the head spine and single medio-dorsal spines on 

 segments 1-3, but also paired rounded tubercles in the middle of segments 3 

 and 4. For this species I therefore propose the name antiguae. 



P. tristanensis does not have paired rounded tubercles at the mid- 

 length of pereonites 3 and 4 and therefore Barnard is probably correct 

 in his separation of these two species. 



Barnard's figures of P. tristanensis bear a remarkable similarity 

 to Fallotritella biscaynensis; however, none of the references mentioned 

 appendages in Pseudaeginella on pereonites 3 and 4 and I must 

 presume their absence. It may be found that appendages are present 

 on pereonites 3 and 4 in the two species of Pseudaeginella; if so, then 

 Fallotritella would probably fall as a junior synonym of this genus. 

 Material of Pseudaeginella was not available to me, and the location 

 of the type material is not known to me. 



Ecology 



Most caprellids seem to be very nonspecific as to the substrate 

 upon which they live; however, most need something to which they 

 can cling and therefore are not found on bare sandy or muddy bot- 

 toms. Species such as Caprella equUibra and Caprella penantis have 

 been collected on various algae, sea grasses, sponges, hydroids, sty- 

 lasterines, alcyonarians, zoantharians, bryozoans, ascidians, and in 

 several unusual habitats. Some caprellids, however, do have a fairly 

 specific habitat preference. Caprella unica is associated with the 

 starfishes Asterias forbesi and A. vulgaris and indeed shows an adapta- 



