370 Mr. F. Walker on some undescribed Ceylon Insects. 



which was partly covered with Hydractinia echinata. Its generic 

 and specific characters are embraced in the following diagnosis: — 



DlCORYNE. 



Char. — Ccenosarc branched, clothed with a polypary and ad- 

 hering by a tubular network. Polypes claviform, of two kinds, 

 one sterile, the other proliferous, both borne upon the common 

 ccenosarc, and issuing from the extremities of the branches. 

 Sterile polypes with a verticil of filiform tentacula situated be- 

 hind the mouth ; proliferous polypes destitute of tentacula (and 

 mouth ?), and having the gonophores clustered round their base. 



D. stricta. Stem rising to the height of about \ an inch, irre- 

 gularly branched; branches ascending at a very acute angle 

 from the stem. Polypary slightly dilated at the extremities of 

 the branches, somewhat corrugated near the base, but without 

 distinct annulations. Tentacula about 16, in a slightly alternat- 

 ing verticil. 



The only specimen of Dicoryne stricta I obtained was male. 

 The polypary possessed but little transparency, and, as well as 

 the polypes, was of a light brown colour. From the basal tubu- 

 lar network, besides the branched colonies, there also sprang 

 unbranched stems which ascended vertically to the length of 

 about a line, and bore each a terminal polype. These are appa- 

 rently young zooids not yet complicated by branching, though 

 many of the polypes seemed to have attained maturity, and pre- 

 sented the same difference of form as in the branched colony, — 

 being in some cases tentaculiferous and sterile polypes ; in others, 

 polypes destitute of tentacles, and loaded with gonophores. 



The habitat of D stricta seems to be entirely similar to that 

 of Hydractinia echinata*. 



XXXIX. — Characters of some apparently undescribed Ceylon 

 Insects. By F. Walker. 



[Continued from vol. iii. p. 265.] 



Order HYMENOPTERA. 



Fam. Formicidse. 



Formica exercita. Fcem. Nigra, densissime et scitissime punc- 

 tata, antennis subfiliformibus, scapo flagelloque apice rufescentibus, 



* In Professor Huxley's beautiful and philosophic memoir on the 

 Oceanic Hydrozoa, just published by the Ray Society, he has proposed a 

 terminology, partly special for the particular groups which form the subject 

 of his memoir, and partly intended to apply to the Hydrozoa in general. 

 I would gladly have adopted several of Professor Huxley's terms in the 

 present paper, if I could have done so without accompanying them with defi- 

 nitions which would have inconveniently increased the length of these notes. 



