KONGL. SV. VET. AKADEMIENS IIANDLINGAR. BAND. 21. N:0 5. 9 



Syn. 1850. Clydonia gracilis, DANA. — Proc. of the Amer. Acad, of Science and 



Arts. Vol. 2, p. 19. 



» » » 1852. United States Exploring Expedition. Cru- 



stacea. Vol. 2, p. 834; pi. 55, fig. 6 

 a — b. 



» » Spence Bate. 1862. Catal. Amph. Crust. Brit. Museum, p. 284; 



pi. 47, fig. 8. 

 Tyro gracilis, » C. Bovallids. 1887 . »Systematical list of the Araphipoda Hy- 



periidea». Bih. t. K. Sv. Ak. Handl. 

 Bd. 11. N:o 16, p. 4. 



As I have never seen any specimen of this species the Avhole description is taken 

 almost literally from Dana, with some few additions, derived from my examination of 

 his drawing. 



The head is short, about half as long as wide, not keeled on the upper side. 



The eyes consist of eight lenses round a central one. 



The first pair of antenna? are stout at the base and gradually taper to an acute apex; 

 they have minute spines on the outer side and are short, pubescent on the inner. 



Along the sides of the segments of the pereion the outline of the epimerals is 

 barely distinguished. The last three pereional segments are as long as the first four. 



The first and second pairs of pereiopoda are short, hirsute, with small dactyli. 

 The second pair are a little longer than the first. 



The third and fourth pairs are longer than the preceding, and very nearly naked. 



The fifth pair are about twice as long as the fourth; the femur is about as long 

 as the next three joints together; the metacarpus is a fourth of the length of the femur; 

 the dactylus is very small. 



The sixth pair are much shorter than the fifth. 



The seventh pair are not half as long as the fifth. 



The first pleonal segment is a little longer than the second. 



The ural segments decrease rapidly in size. 



The uropoda are slender, acute; the interior coalesced ramus of the third pair is 

 almost as long as the peduncle. 



3. TYRO SARSI, C. BOVALLIUS, 1885. 



(PI. I, fig. 1—17; PI. II, fig. 1—10). 



Diagn. Corpus earinatum. Caput tertia parte altius quam longius, superne earinatum, carinis diver- 

 gentibus. Antenna' primi paris corpore paullo breviores. Pedes pereii primi paris carpis 

 ac dactylis elongatis. Pedes quinti paris pedibus sexti paris multo longiores; femur ante 

 leviter, post distincte serratum, articulis tribus sequentibus multo brevius, spinam rectam, 

 genu duplo longiorem, gerens; tibia carpo multo brevior, carpus metacarpo ter fere longior. 



K. Vet. Akad. Handl. Band. 21. N:o 5. ^ 



