Fauna Suhterraneee. 149 



divisa spuria ; tarsi ovine s biarticulali. Abdomen metnbrana- 

 ceum, scutis corneis obsoletis. Corpus selulosum, setis simpli- 

 cibus. 

 BXwfJpog, a fiXwa^w. 



Blothrus Spel.&us. 



Pallide ferrugineus, manibus obscurioribus apice fuscescentibus, 

 abdomine animalis vivi eburneo. Long. 2| — 2| lin. 



Tn places of the caves, where water drops down direct upon the 

 floor, small collections of it take place, which form a deposit of 

 crystals of carbonate of lime at their bottom. In these pools in 

 the Luege and Adelsberg caves, we find a snow-white, blind, crus- 

 taceous animal of the family of Amphipoda. It has a slender 

 smooth figure, without any spines, and so nearly allied to Gam- 

 marus, that it would belong to that genus, were it not for its want 

 of eyes, and the following very striking character : — The last ab- 

 dominal feet, which are nearly void of spines, have the inner style 

 rudimentary, while the outer is not only greatly elongated, espe- 

 cially in the male ; but what is more remarkable, it is two-jointed. 

 I consider this last circumstance as decisive, being supported in 

 this view by some expressions of our celebrated Carcinologist 

 (M. Kroyer), concerning those species of Gammarus, in which 

 the style of the second joint of the sixth pair of abdominal legs 

 is rudimentary, or entirely wanting ; such as G. Olivii, podager, 

 Dugesii, brevicaudaius, Milne-Edw.,* affinis and pungens, Milne- 

 Edw.,-|- dentatus% and anisochir, K.§ He considers this structure 

 to be of weight in a physiological point of view, as a generic cha- 

 racter among animals, whose motion in a great measure consists 

 in jumping ;|| but in our new species, this apparatus for jumping 

 differs still more, so as to resemble almost a rotatory contrivance. 

 Another deviation deserving notice, is the very slight development 

 of the appendicular flagellum of the uppermost antennae, which 

 consists of only two joints, and protrudes very little beyond the 

 first joint of the flagellum ; yet great weight cannot be attached 

 to this structure, especially as in some degree it occurs in several 



* Extrait de Recherches pour servir a l'Hist. Nat. des Crustaces-Amphipodes 

 (Annal. des Sc. Nat. torn. xx. p. 367—372). 

 •f- Hist. Nat. des Crustac£s, torn. iii. p. 47. 

 J Kroyer, Naturhist. Tidsskr. vol. iv. p. 159. 

 § Ibid. New Series, vol. i. p. 327. 

 || Kroyer, lo. cit. p. 326. 



