INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 435 



s-ate, in E, Pallasii, T. Moehii, and T. Baronii the sexes are exactly 

 similar in size, in external form, and in organization. 



Free Terrestrial and Fresh-water Nematoda of Holland.* — In 

 this paper Dr. De Max only enters into the systematic portion of his 

 subject ; the paper extends over one hundred pages, and contains 

 descriptions of several new genera and species, together with an 

 account of forms already described, and a list of the names of the 

 forms described. A hundred and forty-one species are described, and 

 of these twelve only are exclusively inhabitants of fresh water, the 

 rest live on or near the roots of various plants ; in order to shorten 

 the descriptions, parts which are continually referred to are spoken of 

 by symbols (taken from the Greek alphabet). 



Like Bastiania, already described by the author, the new genera 

 Alaimus, Deontolaimus, and Aphanolaimus have no buccal cavity ; the 

 first of these has no accessory pieces connected with the genital 

 spicula, the second has a rod-shaped accessory piece, and the third, in 

 addition to an accessory piece, has, in the male, a median row of four 

 chitinous efferent ducts in front of the anus. In the new genus 

 Desmolaimus the buccal cavity is very small, has very thin walls, 

 and is provided with three concentric chitinous thickenings, the 

 innermost of which extends along the base of the cavity ; Microlaimus 

 (nov. gen.) has likewise a small buccal cavity, but it is distinguished 

 by the presence of a feebly developed, dorsally-placed denticle. 

 Ethmolaimus is again a new genus, which is distinguished by having 

 the chitinous walls of its buccal cavity made up of two parts ; the 

 anterior portion has longitudinal ridges, and the posterior is formed 

 by a circular chitinous process which separates the anterior from the 

 succeeding portion of the buccal cavity. The sixteenth genus in the 

 list is also a new one, and receives the name of Ghoanolahnus from the 

 funnel-like shape of its buccal cavity, which has chitinous walls, and 

 is formed of an anterior wider, and a posterior narrower portion ; it 

 is without teeth. Aulolaimus is likewise distinguished by the form 

 of its buccal cavity, which is here greatly elongated and tubular ; it is 

 very narrow, is longer than the true oesophagus, and has chitinous walls. 

 Prismatolahmis, which comes next, has a buccal cavity of a short 

 prismatic form, without teeth or any armature, but with chitinous 

 walls. Lcptolahmis has been already described by the author ; it has 

 an elongated buccal cavity, which is tubular, but has very thin walls 

 and no teeth. Cijlindrolaimus is the name of a new genus, witli a 

 buccal cavity forming an elongated cylindrical tube with chitinous 

 walls. Bhahdolaimus has its buccal cavity greatly elongated and 

 very narrow, but it is further distinguished by being bounded by 

 three chitinous rods, which converge a little, posteriorly, and have 

 connected with their anterior end a small hook-shaped body, which is, 

 perhaps, movable. The greatly elongated and very narrow buccal 

 cavity of Odmilolaimns is diKtiiiguishod by having at its commcnce- 

 iiicnt ii triiingular, dorso-mcdian, chitinous tooth. The new genus 

 Diptherojjhora is somewhat remarkable, for its oval, elongated, 



* 'Tijd. Nodcrl. Dicik. Vcrcon.,' v. (18S0) p. 1. 



