M. Hesse on a new Parasitic Crustacean. 81 



(and this is a special character of the Lermeida), that there 

 exists all round the body a transparent border, which accompa- 

 nies its outline through all its circumvolutions. 



Moreover a circumstance which has no less attracted our at- 

 tention, and which, in our opinion, is most curious, is the resem- 

 blance existing in the mode of life of the two parasites. 



We know, in fact, that Lernaa hranchialis, by means of its 

 buccal apparatus, which, as in our parasite, does not appear to 

 furnish any resources for this purpose, and which appears rather 

 destined to draw up liquid materials by suction, succeeds never- 

 theless, in course of time, in perforating the very thick and re- 

 sistant first wall of the branchial arch of fishes, in order to lodge 

 its radiciform frontal system in the space occurring between the 

 two plates of this bony part. Our parasite, by similar actions, 

 also, by separating and raising the two laminae which form the 

 scales of the fish on which it has estabhshed itself, succeeds in 

 altering their structure, thus creating for itself a refuge in which 

 it is entirely lodged, and where it lives in peace and sheltered 

 from all dangers. 



From what has gone before, and notwithstanding the diflfer- 

 ences existing between the two species which we compare, we 

 do not hesitate to think that they must belong to the same 

 order; and we form for our parasite a new family, which we 

 characterize as follows : — 



Family Lemaeosiphonostomea. 



The females fixed upon their victim by means of the scales 

 of the latter, in which they hollow out a residence. Several 

 footjaws placed around the mouth. Head not horned. Ovi- 

 ferous pouch large and flat. 



Genus Leposphilus*, nobis. 



Body fusiform, divided into ten [eleven] segments, which are 

 very distinct, with the exception of the third and fourth ; of 

 these, four [five] are thoracic and six abdominal ; all surrounded 

 by a transparent border. Head small, rounded at the apex, bear- 

 ing above a median eye, and beneath presenting the buccal 

 orifice, which emits, in a proboscidifortn process, some denticu- 

 lated jaws adapted for the trituration of objects, and laterally three 

 pairs of prehensile footjaws. Antenna very small, rounded at the 

 end, and terminated by divergent hairs. Abdominal segments 

 retractile, and capable of invagination ; last segments terminated 

 by divergent appendages. Embryo ovulate, furnished with three 



• This name ought evidently to be Lepidophilus, and the specific name 

 Labri, instead of Lubrei. 



