on some new Entomostraca. 15 



corporis longitudine, setis brevibus, apicalibus tamen sub- 

 longis, numero minimum viginti et conspicui. Abdomen 

 3-articulatum. Styli caudales breves. 



The inequality in length of the anterior antennae, and the thick 

 pencil at the end of the same organs, make it very easy to aistin- 

 guish this species from any other. I only possessed one specimen, 

 which I was obliged to dissect in order to examine the different 

 appendages. The two branches of the second pair of antennae 

 are nearly equal in size. The basal part of the lateral branch is 

 indistinctly divided into several segments, and has about six long 

 hairs. Length *03. 



The first pair of maxillae are "Ol 8, the second pair "01 5, and the 

 maxillipeds "032 in length. All these organs are formed as usual 

 in Calanus. 



The first pair of legs are "032 in length ; both the branches are 

 three-jointed, and have a hair at the apex of each of the four basal 

 segments ; the apical segment of the outer branch has three hairs 

 on the margin and two at the apex, besides a curved spine. That 

 of the inner branch has also three at the margin and two at the 

 apex. 



The fourth and fifth pairs were, unluckily, imperfect. 



The abdomen is short, and the caudal stylets are rather longer 

 than the posterior abdominal segment. The terminal setae have 

 been broken off. 



Length of cephalothorax ....•] 00. 

 ,, abdomen '026. 



PI. IV., figs. 1, 3. 



C. lalus, n. sp. 



Rostrum breve. Frons rotundatus. Cephalothorax 5-articula- 

 tus, postice obtusus. Antennas anticse corpore vix breviores, 

 setis quibusdam longis, und apicali praelongd, postica penul- 

 timd longa ; anticd penultima ante-penultimisque brevibus. 

 Antennae postice brevissimse, appendice laterali tamen longa. 

 Pedes natatorii primi paris, ramis 2 et 1-articulatis, quarti 

 paris 3-ariiculatis. Abdomen 4-articulatum stylis brevibus, 

 setis quatuor subaequis. 



The hairs on the anterior antenna are short, but about every 

 fourth segment there is one considerably longer than the others. 

 The length of the organ is '135, which is very nearly that of the 

 body. 



The second pair of antennae are remarkable. The lateral ap- 



