1909.] ON A NEW SPECIES OF CRAB FROM THE BAY OF BATAVIA. 663 



the fishes dealt with in this paper into Bottom Fishes, Sluggish 

 Shallow-water Fishes, and Free-swimming Open-water Fishes. 



When tabulated thus there is seen to be practically no con- 

 nection between the structui-e of the nose, particularly as regards 

 the presence or absence of accessory sacs, and the general life- 

 habit. Thus fishes of all habits may have accessory sacs [Jhdlus, 

 Pleuronectids, Scomber, Herrings, Perch), or not (Eels, some 

 Siluroids, Carps, Pike, Scopelus, Gadus, Exoccetus). This is a 

 conclusion somewhat at variance with Kyle's generalization, that 

 accessory sacs are characteristic of bottom or sluggish fishes as 

 opposed to free-swimming forms and are in the main adaptive 

 structures determined by habit. 



On the contrary, it would appear from the above that they are 

 rather part of a general advance in structure, and belong, at least 

 in their most chaiacteristic development, to families that have 

 reached the highest all-round development. 



Explanation of Abbreviations in the Text-figtjees. 



A.N. , anterior nostril. ADD.M., adductor mandibulse. AOR., antorbital scutes. 

 AX., axis of rosette ; AX.', its connection with lip of anterior nostril. B.M., buccal 

 membrane. C, central segment of lamina. CT., curtain-like extension of bridge 

 between nostrils. E., e3'e. E.MX.L., ethmo-maxillary ligament. ETH.P.A., 

 ethmo-palatine articulation. ETH.S., ethmoidal nasal sac. FR., frontal. H., hood- 

 like process of posterior lip of anterior nostril. L., linguiform process of lamina. 

 LAC, lachrymal scute. L.ETH., lateral ethmoid ; L.ETH.', its articular process 

 for the lachrymal. LM., lamina. L.S., lachrymal nasal sac. MD., mandible. 

 METH., mesethmoid. MX., maxilla. N., nasal. N.S., nasal sac. OL.B., olfactory 

 bulb. OL.C, olfactory cavity. OL.N., olfactory nerve. P., peripheral segment of 

 lamina. PA., palatine. P.MX., premaxilla ; P.MX.A., palato-maxillary articu- 

 lation. P.PMX.L., palato-premaxillary ligament. P.N. , posterior nares. R., rosette. 

 R.MX., retractor maxilla?. R.PMX., retractor premaxillse. T., tentacle. 



4. Description of a new Species of the Genus Alpheus Fabr. 

 from (he Bay of Batavia. By J. G. de Max *. 



[Received April 30, 1909.] 



(Plate LXX. t) 



Alpheus ehlersii, sp. n. 



Syn. : Alpheus macrochirxis de Man, in Archiv fiir Naturg. 

 53 Jahrg. (Berlin, 1888), p. 519. 



A re-examination of the two specimens of Al])heus from the 

 island of Edam, Bay of Batavia, described by me {I. c.) under the 

 name of A. macrochirus Kichters, not only proved that they had 

 been wrongly referred to that species, but also that they are the 

 repi'esentatives of a hitherto unknown form. This new species, 

 which I have the pleasure to dedicate to Professor Ehlers of 



* Communicated by R. I. PococK, F.L.S., F.Z.S. 

 t For explanation of the Plate see p. 666. 



