930 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvi. 



Allon-hcfifcs Imicl-erhockerl Bate/' as pointed out by Professor Smith 

 himself." It ma}^ be convenient to accept Saussure's name for the, 

 dentate form, although his description is vague and his figures rough.! 

 In the large second gnathopod, of which he gives a detailed figure,] 

 the wrist or fifth joint is entirely devoid of the characteristic project-' 

 ing process. In my opinion the same motive of convenience is sufii- 

 ciently strong to justify the retention of the specific name inermh for 

 the form that is not dentate. This I have applied to specimens 

 obtained by Mr. Edward Whymper at great heights in Ecuador.^ 

 None of these had dentate body segments. On first examining the 

 specimens from Costa Rica, I was disposed to identify them with the 

 species submitted to me by Mr. Whymper. About the close general 

 resemblance there can be no question, but in detail I find the follow- 

 ing difi'erences: The new species here described has the antenna? of 

 both pairs more elongate, the first joint in the third, fourth, and fifth 

 pera?opods larger and more broadly oval, and the postero-lateral 

 angles of the third pleon segment much more decidedly produced. 

 None of these characters, it must be confessed, are easy to appreciate 

 except by comparison of actual specimens or of accurate figures 

 drawn to the same scale. But the mouth organs show a curious fea- 

 ture, in that the first maxillae, as above stated, have three set?e on the 

 apex of the inner plate, alike in male and female, while IL inermfs 

 has onl}" two. In the male of II. faxmu the first gnathopods have the 

 hand not, or very little, broader at the palm than in the middle, 

 whereas the II. hiermis from Ecuador has a strong bulging of the 

 palm beyond the point which the finger reaches, making the hand as 

 broad as it is long. Also in the large second gnathopods there is a 

 stronger bulge at the corresponding point, making the breadth of the 

 hand in the Ecuador species greater in proportion to its length, and 

 the ' ' notch " at the other end of the palm is rounded off. 



EXPLANATION OF PLATES. 

 Plate LX. 



Talorcliedia fritzi, new .yieciat. 



n. s. Length of male Rpecimen examined, not including the antennpe. 



a. .s-., a. I. The uijper and lower antennae, respectively, of the two sexes, with further 



enlargement of two joints of the flagellum in lower antennae of male. 

 gn. 1, gn. 2. First and second gnathopods, respectively, of the two sexes, with further 



enlargement of some of the distal joints. 

 iwp. 2. 9 . Second peraeopod of the female, with enlargement of finger. 

 prp. 5. Fifth pergeopod of the male. 



« Catalogue of the specimens of Amphipodous Crustacea in the Collection of the 

 British Museum, 1862, p. 36, pi. vi, fig. 1. 



^Travels among the Great Andes of the Equator, Appendix, 1891, p. 125. 



