CRUSTACEA PEOM KUTCH AND SIND. 3 



Mr. Wynne in the same argillaceous beds of the nummulitic series between Sooja- 

 poor and Badra, and also to the north of the former locality, in Kutch. 



Family,— FOBTUNID^. 



G'emfs,— NEPTUNUS, Haan. 



The species of Neptunms are easily distinguished from the allied genera, Soylla, 

 Lupa, and Acheldus,' by having the last, or costal spine, considerably longer than 

 the remaining eight spines of the antero-lateral margin. 



The recent species are tolerably numerous in the Eastern and American seas ; 

 one also occurs in the Mediterranean. Of fossil forms Al. Milne-Edwards 

 only lately described six tertiary species, one from Erance, one from Sardinia, 

 and four from Northern Italy (Vicentin), fVide Hist, des crust. Podophthal. foss., 

 vol. i, 1861-66, p. 106, et seq.). To these I have to add two new species from the 

 tertiary beds of Sind, N. Wyrmecmus and Sindensis. They exhibit some pecu- 

 liarities which deserve special mention, because they throw some light upon the 

 value of certain characters in the poetunidm. 



Haan (in Eauna Japonica) distinguished three equivalent sub-genera, Neptunus, 

 Amphitrite, and Pontus. They are all characterized by the large size of the costal 

 spine. The sub-divisions are made according to the form of the third endopodite 

 joint of the outer maxillary feet. In Neptunus this joint is longer than broad, 

 with the lower inner angle conspicuously produced, and with the upper hinder 

 edge rounded. In Amphitrite the upper hinder edge of the third endopodite is con- 

 siderably produced and also rounded. In Pontus the same joint is said to be square. 

 The last sub-genus is based upon a new species not further characterized. Amphitrite 

 was accepted by Dana, but united with Neptunus by Milne-Edwards. The charac- 

 ter relating to the form of the third joint seems to be subordinate, but it is remark- 

 able to find the Ampitrife-£orm already represented in fossil species, as may be seen 

 from the examination of N Wynneanus. This shows that the character in question 

 possesses a certain constancy, and that some classiflcatory value may be attached to 

 it. It would probably be convenient to retain Amphitrite as a sub-genus of 

 Neptunus, though under a different denomination, Amphitrite having been already 

 used by Miiller in 1771 as a generic name. In the other species which I shall 

 notice, Nept. Sindensis, the third endopodite of the outer maxillipeds is not pre- 

 served, but both species agree in one or two other points. 



In the typical Neptunus (type, N. pelagicusj the antennulary ridge is ante- 

 riorly produced into a sharp spine which projects beyond the front margin. In 

 the two Indian fossil species the spine is indicated, but does not even reach the 

 margin. I also do not see it indicated in the figures of the species, referred by de 

 Haan to Amphitrite, and as I have no recent examples of this to compare, I 

 cannot say what importance is to be attached to the development of this spine, but 

 it appears that, if Milne-Edwards is correct in identifying the three forms under 

 one genus, as he has done, the long inter-antennulary spine cannot be regarded as 

 an essential character of Neptunus. 



