CRUSTACEA MALACOSTRACA. III. 



J 53 



does the present species." (M. Murrayi); but this quotation shows that at least neither Walker nor 

 Stephensen had read my text, as I wrote (1895) on M. longicornis: "in dem Ban der Schwimmfusse 

 mid Uropoden (so weit sie vorhandeu sind) stimmt es mehr rait Munnopsis typica M. Sars als rait 

 Eurycope gigantea G. O. Sars uberein, aber es weicht in dem Ban der Mandibeln griindlich von beiden 

 ab". These words ma)' prove sufficiently that it was very easy for Sars to point out that difference. 

 M. longicornis H. J. H. is allied to M. oceanica Tatt. and M. spinifer Vauhoffen (1914). Of the remaining 

 species referred to Munnopsis, M. australis Bedd. will be mentioned presently; M. latifrons Bedd. and 

 M. longircmis Richardson are closely allied but, like M. gracilis Bedd., too imperfectly known for discus- 

 sion on affinities. 



The material from our area comprises four species, viz. Munnopsis typica M. Sars, M. oceanica 

 Tatt., a new species closely allied to M. australis Bedd., and the form described by Tattersall as Mun- 

 nopsoides Beddardi Tatt. But a study of these forms showed that it was necessary to divide the genus 

 Munnopsis into three genera. M. typica has the anterior thoracic segments and especially third segment 

 much broader than the rather narrow three posterior segments, and these three are immovably coalesced 

 with each other and with the abdomen; the mandibles have no molar process, well developed palp, 

 and on the left mandible only rudiments of setse near the lacinia; the natatory legs have the two 

 distal joints moderately broad; in the male the second pair of pleopods are free to the base with their 

 copulatory organ extremely elongate, and the uropods are moderately long; this species must of course 

 remain as the type for the genus Munnopsis M. Sars. But M. oceanica Tatt. must be removed; it agrees 

 with M. typica in having well developed mandibular palps, but the mandibles have a number of well 

 developed setse before the incisive dentate part and a slender conical molar process; the difference in 

 breadth between the anterior and the posterior thoracic segments is moderate; the three posterior seg- 

 ments and the abdomen are movable, the fifth joint of the natatory legs is much broader than the sixth; 

 the male pleopods of second pair have their proximal part completely fused in the median line, and 

 the copulatory organs moderately elongate; the uropods are long. For the reception of M. oceanica 

 Tatt. the generic name Paramunnopsis is proposed. 



Munnopsis australis Beddard has by Tattersall been taken as type for his genus Munnopsozdes, 

 to which he also referred his new species M. Beddardi Tatt. Supposing that M. australis in the main 

 features agrees with my M. eximius n. sp. (described later on) these three species show the following 

 features. They agree with Munnopsis typica and differ from Paramunnopsis n. gen. in having no molar 

 process and the sette rudimentary on the mandibles, and, besides, in the fact that the three posterior 

 thoracic segments and the abdomen are immovably fused ; they differ from both in some features, viz. 

 the mandibles have no palp, the anterior thoracic segments are very broad and the posterior very narrow, 

 the fifth segment even extremely narrow, the natatory legs have the two distal joints very narrow, 

 and the uropods are very short. But in one most interesting feature the two species M. Beddardi Tatt. 

 and M. eximius n. sp. are very different. In M. eximius and therefore, according to the above-named 

 supposition, in M. australis Bedd., the male pleopods of second pair are quite independent, and the free 

 part of their copulatory organ more than twice as long as the pleopod (PI. XIV, fig. 211); in the male 

 of M. Beddardi Tatt. the same pleopods are fused to such a degree that they constitute a single large 

 plate (PL XIY, fig. 3 k) with a posterior oblong incision, in which are found the two copulatory organs, 



The Ingolf- Expedition. III. >. 2 ° 



