174 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



In 1905, Tattersall a follows Milne Edwards in referring Ncesa de- 

 pressa to Leach. Leach, however, never described this form, the 

 earliest description having been given by Say in 1818, and the next to 

 follow being that of Milne Edwards in 1840. Tattersall says of this 

 species (p. 65) in connection with remarks on the distribution of 

 Bathycopea typhlops, an allied form : 



It is to be regretted that the locality of Ancinus depressus Leach is unknown. 

 It would have been interesting to have compared the habitats of the two forms. 



Milne Edwards also says of Ancinus depressus " Patrie inconnue." 

 Say gives the locality of the specimen of Ancinus depressus placed 

 in the Academy of Natural Sciences of Philadelphia as Egg Harbor, 

 New Jersey. White mentions North America as the habitat of the 

 specimen presented by Thomas Say to the British Museum. 



In 1905, Tattersall instituted the family Anciniidw for the reception 

 of this genus and his new genus Bathycopea. In the same year 

 Hansen created the section Ancinini of the Sphceromince platy- 

 branchiatce to include this genus, as well as his new genus Ancinella 

 and Tecticeps Richardson. Ancinus differs, however, from any 

 of the genera mentioned in the character of the first and second pairs 

 of pleopoda, the first of which are single branched instead of double 

 branched. 6 For this reason it can not be left where it has been placed 

 in the classifications proposed by these authors. 0 



Last spring in the material that came to the U. S. National Museum 

 from Prof. A. E. Verrill was a single specimen of Ancinus depressus, 

 collected at Woods Hole, Massachusetts, in 1885, by the U. S. Bureau 

 of Fisheries steamer Albatross. It was found at a depth of 2-3 

 fathoms. The specimen is a female and, although it differs slightly 

 from the figures given by Milne Edwards for this form, I am in- 

 clined to think that the differences are perhaps sexual. The uropods 

 are slightly shorter and the first pair of legs have the hand more 

 enlarged. In the shorter uropoda, however, it agrees with the dried 

 specimen in the Academy of Natural Sciences of Philadelphia.^ As 

 no complete figure has ever been given since that of Milne Edwards, 

 I have thought it would be of interest to figure and redescribe this 

 specimen, which has been preserved in alcohol, and also give some de- 

 tailed drawings of parts which it has been impossible to study in the 

 dried specimens. 



0 Fisheries Ireland Sci. Invest., 1904, II, 1905, p. 11. 

 & See description and figures which are to follow. 



c I prefer to retain Ancinus as the type and only genus of the family An- 

 ciniidw, but those who desire to follow the classification of Hansen may 

 accept the name Spwrominw colobranchiatw for a fourth group to include this 

 form. 



d See figure in Bull. U. S. Nat. Mus., No. 54, 1905, p. 272. 



