53 



liroad, armed on tlie inner edge with small olaw-like spines, hasal lobe 

 obtusely truncated at the tiji, ])ali) rather large, daetylus slender s])iniform. 

 Both paii's of gnatliopoda very slender and about of same length, the anterior 

 ones with the propodos narrow and elongated, provided at the tip with a doiible 

 row of delicate setae, daetylus replaced by a dense lu'ush of hair-like setae, 

 though a claw-like rudiment may be found on closer examination; propodos 

 of the posterior pair produced at the tip beneath the daetylus, thus forming 

 a minute chela. Pereiopoda rather strong, the 3 posterior pairs successively 

 increasing in length; basal joint very broad, laminar; meral joint likewise 

 cousideralily dilated, especialh' in the third pair. Last pair of uropoda 

 considerably projecting bej^ond the preceding pair, rami subequal, denticulated 

 and setous. Telson elongated and narrow, deeply cleft. 



liemarJiS. — The present genus was established by Costa as early 

 as 1851 for a Mediterranean species C. Hopei, to which was subsecpiently 

 added by the same author another species C. punctatmn. The genus Scopelo- 

 cheirits established by Sp. Bate in 1855 for a British species, is undoubtedly 

 identical with the genus of Costa and thus must cede to the elder name 

 CaUisoma. It is a very distinct geniis, differing from the other Lysianassidse 

 both in the structiire of the oral parts and especially in that of the gnatho- 

 poda, the anterior pair of which are very peculiarly constructed. Two closely 

 allied, though evidently distinct, species belong to the Fauna of Norway. 



13 Callisoma crenata, Sp. Bate. 



(I'l. m, % 1). 



Scopelocheirus crenatus, Sp. Bate, Brit. Assoc. Report 1855. 

 Body rather robust, with broadly rounded back. Cephalon comparatively 

 small, lateral corners but slightly projecting and narrowly rounded. First 

 pair of coxal plates rather broad, completely obtecting at the sides the buccal 

 mass, their anterior and inferior edges forming a quite continuoiis curve; 4th 

 pair deeply emarginated posteriorly and below the emargination augulai-ly 

 produced; 5th pair much broader than they are deep. Last pair of epimeral 

 plates of metasome rounded at the lateral corners, posterior edge irregularly 

 crenulated. First segment of urosome having dorsally a deep transversal 

 incision, below which there is a rounded carina. Eyes broadly oval, pigment 

 reddish l)rown with an orange-coloured (seating. Superior antennse about 

 twice the length of the cephalon, peduncle short and thick, especially in the 

 male; flagellum 10— 12-articnlate, 1st joint in female about the length of the 

 3 succeeding joints combined, in male nearly occupying the half length of 

 the flagellum; accessory appendage 3-articulate. Liferior antenna:' in female 



8 — Crustacea. 



