82 U.S. NATIONAL MUSEUM BULLETIN 2 78 



types USNM 120174. Hummelinck sta. 1423a, Bahia Fosforescente, 

 Puerto Rico, 1 m, Sept. 17, 1963, 1 female paratype USNM 120175. 

 St. John, Virgin Islands, 29 m. Mar. 17, 1906, 1 female paratype 

 Copenhagen Mus. St. Croix, Virgin Islands, 7 m, Feb. 19, 1906, 5 

 male, 5 female, and 2 juvenile para types Copenhagen Mus. 



Remarks. — ^The genus Metaprotella was hitherto composed of 7 

 species, M. ajricana Mayer, 1903; M. danae (Kossmann, 1880); M. 

 excentrica Mayer, 1890; M. haswelliana (Mayer, 1882); M. makro- 

 dactylos Stebbing, 1910a; M. problematica Mayer, 1890; and M. 

 sandalensis Mayer, 1898. All of these species have spiny bodies or 

 at least a cephalic spine with the exception of M. jJfohlematica which 

 is almost smooth. M. hummelincki differs from M. problematica in 

 that the latter species does not bear the papillae at the tip of the 

 male abdominal appendage and the inner margin of the outer lobe 

 of maxilliped is toothed and not covered with setules. 



Mayer (1903) gave a short description of a Metaprotella sp. from 

 St. Croix. He stated that perhaps this species belonged to M. prob- 

 lematica; it differs, however, in having oval gills instead of rod shaped. 

 The gills in M. hummelincki are elliptical or cylindrical. Thus, I 

 cannot be certain that M. hummelincki is the species to which Mayer's 

 M. sp. should be referred. It is unlikely that another species of Meta- 

 protella is present in the Caribbean and since M. hummelincki has 

 been collected from St. Croix, Mayer's A/, sp. has provisionally been 

 assigned to this species. 



The species name is in honor of P. Wagenaar Hummelinck of the 

 Zoologisch Laboratorium in the Netherlands, who kindly supplied 

 me with some of the material upon which this species is based. 



The only habitat record available for this species is from Thalassia. 



Paracaprella Mayer, 1890 



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

 dibular palp 0- to 3-segmented, when 3-segmented articles reduced 

 as compared to Deutella, setal formula for terminal article 1, molar 

 present; outer lobe of maxilliped larger than inner lobe; gills on 

 pereonites 3 and 4; pereopods 3 and 4, 2-segmented, pereopod 5, 

 6-segmented; abdomen of male with pair of appendages and pair of 

 lobes, female with pair of lobes. 



Type-species: Paracaprella pusilla Mayer, 1890 (by monotypy). 



Remarks. — See remarks of Deutella on p. 53. 



Paracaprella pusilla Mayer, 1890 



Figures 32a-b, 41, 42, 53 



Paracaprella vusilla Mayer, 1890, p. 41, pi. 1, figs. 28-30, pi. 3, figs. 45-47, pi. 5, 

 figs. 48-49, pi. 6, fig. 10; 1903, p. 67, pi. 2, figs. 36-37, pi. 7, fig. 52.— Schel- 



