KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 351 



with a strong prehensile organ, resembling the claw of some of the Cancridce. The last two pairs 

 of legs shorter than the preceding, and subequal. The three pairs of caudal appendages long and 

 slender, each furnished with two lanceolate branches. Telson short. 



Sexual differences. — Males smaller than the females. In the female the inferior antenna; 

 are absent. In the position of these organs — beneath the lateral eye — is a broad, rounded 

 prominence, slightly projecting beyond the anterior margin of the head. The apex of this pro- 

 minence usually bears a single short hair. The superior antennas are short and three-jointed, 

 the last joint being beset with a few auditory hairs. In the male both pairs of antennas are 

 present, and are provided with long, flexible flagella; the last joint of the peduncle of the su- 

 perior pair long, as in the female, but much more robust, and densely furnished with hairs; the 

 peduncle of the inferior pair three-jointed. The abdomen of the male is stouter, and the bases 

 of the swimming feet more nearly rounded ; in the female the basal portion of these feet are 

 oblong-ovate, and the last segment of the thorax is longer and narrower than the corresponding 

 part in the male.» 



In 1885 Carus translated in Latin the diagnosis of Claus (from 1879) in a some- 

 what condensed form. 



In 1886' Gerstaecker gave a diagnosis, which contains some new characteristics. 



It runs: 



»Kopf kurz, nach unten long ausgezogen. Beide Fvihlerpaare des Mannchens verlangert, 

 die oberen mit langem, dicht buschigem Endglied des Schaftes; beim Weibchen die oberen 

 kurz, zweigliedrig, die unteren nur als Hocker angedeutet. Kiefertaster beiden Geschlechtern 

 fehlend. Die beiden ersten Mittelleibssegmente stark verkiirzt, aber frei, das verlangerte siebente 

 nach hinten stark verjiingt. Die beiden vorderen Beinpaare verkiirzt, in eine schwache Greif- 

 hand endigend, das armformig verlangerte fiinfte mit machtig entwickelter Scheerenhand. Drei 

 Paare von Kiemenschlauchen am vierten bis sechsten Mittelleibsringe. Die Spaltbeine der drei 

 grossen vorderen Hinterleibsringe mit sehr breitem lamellosem Schaftgliede; auch die griffel- 

 formigen Spaltbeine zu drei Paaren ausgebildet.» 



The first described species was as mentioned above Cancer sedentarius, Forskal. 

 The next new specific name was Phronima custos, proposed in 1816 by Risso, it is how- 

 ever only a synonym for Ph. sedentaria. In 1832 A. Cocco described Bivonia Zan- 

 zara, n. sp., which probably is identical with Phronima sedentaria. In 1836 Guerin 

 proposed the two new species Phronima atlantica and Ph. solitaria. In 1862 Spence 

 Bate briefly described Ph. Borneensis, n. sp., which must be considered as identical with 

 Ph. sedentaria. In 1875 Powell proposed the new species Ph. Novce Zealandice, 

 which also is identical with Ph. sedentaria. In 1886 Thomson and Chilton changed 

 the name to Ph. neozelanica. In 1877 Streets described the new species Ph. pacifica. 

 In 1887 I gave short diagnoses of two new species Ph. spinosa and Ph. Colletti. In 

 the same year Giles described and delineated Ph. bucephala, which in my opinion is sy- 

 nonymous with Ph. Colletti. In 1888 Stebbing described Ph. megalodus, n. sp., which 

 I consider to be identical with Ph. solitaria, and Ph. tenella, n. sp., which shows a 

 transition to the genus Phronimella. In 1889 A. Chun 1 ) described Ph. Diogenes, n. sp., 

 which certainly is identical with Ph. Colletti. 



The following list shows the synonyms of the hitherto named species, according 

 to my views as to the nomenclature; but it must be remarked here that almost all these 



l ) A. Chun. »Bericht iiber eine nach den Canarischen Inseln im Winter 1887 — 88 ausgefiihrte Reise. 

 II». Sitzungsberichte der K. Preussischen Akademie der Wissenschaften zu Berlin. 1889, p. 527, pi. 3, fig. 5 — 6. 



