Linncean Society, 519 



A living species which the author is unable to distinguish from 

 the fossil Echinus monilis, Defr., was found very abundantly at the 

 depth of between twenty and a hundred fathoms. It would appear 

 to be the same with Ech. pulchellus, Risso, and a variety Ech. deco- 

 ratus, Agass. It is also Ech. miliaris of Gnibe, but very distinct 

 from the true Ech. miliaris. 



Gen. CiDARis, Lam. 



Species of Cidaris Hystrix, Lam., were frequently met with, but 

 perfect specimens are not so common. They are occasionally, how- 

 ever, found in considerable numbers and appeared to be gregarious, 

 between thirty and forty living examples having been taken in a 

 single dredge in seventy fathoms water off Cape Krio in Asia Minor, 

 the site of the ancient city of Cnidos. The author gives a particular 

 account of the differences between this species and Cid. papillaris of 

 the British and Norwegian seas, and observes that it possesses the 

 power of climbing up branching bodies by means of its spines alone. 

 He thinks it possible that the perforated tubercles of this genus may 

 have reference to this habit, the additional ligament giving additional 

 firmness to the long spine. 



February 6. — R. Brown, Esq., V.P., in the Chair. 



Read " Descriptions of the Nests of two Hymenopterous Insects 

 inhabiting Brazil, and of the species by which they were constructed." 

 By John Curtis, Esq., F.L.S. 



The materials for this paper were obtained by Mr. Curtis from a 

 collection in the possession of Lord Goderich, to whom it was pre- 

 sented by the Right Hon. Henry Ellis, on his return from his late 

 special mission to Brazil. 



The first insect described belongs to the family of Tenthredinida 

 and to the genus Hylotoma of Klug. But this extensive group, as Mr. 

 Curtis has already remarked, affording sufficient grounds for further 

 generic subdivision, he has distinguished the present species by the 

 following name and characters : — 



DiELOCERus, Curt. 



Antenn(B articulo 3tio in mare furcato, piloso ; in foemina simplici. 

 Tibice ante apicem espinosae. Clypeus profunde emarginatus. Labrum 

 orbiculare: mandibulce graciles, acutae, altera denticulo interno mi- 

 nuto : maxillcB subaequaliter bilobae ; palpi mediocres, 6-articulati, arti- 

 culis tribus basalibus sequalibus, secundo tertioque crassis, quarto 

 paulo minore, quinto omnium minimo quadrato, sexto gracili, baud 

 reliquis longiore : mentum sub-semiovatum ; palpi tuberculis promi- 

 nentibus affixi, breves, crassi, 4-articulati, articulo secundo latiore, 

 tertio omnium gracillimo longitudine primi : labium latum, trilobum. 



This genus is most nearly related to Schizocerus, Latr. The 

 species on which it is founded is named by Mr. Curtis Dielocerus 

 Ellisii, and is described at length, and the distinctions pointed out 

 between it and Hylotoma formosa, Klug, to which Mr. Curtis was 

 at first inclined to refer it. Its economy is totally different from 



