CRUSTACEA MALACOSTRACA IV. 6j 



a little longer than the two posterior abdominal segments combined, with slightly more than its proximal 

 two-thirds cylindrical and no vestige of lateral teeth on this part ; the distal part much narroved towards 

 the end which terminates in two short spines, while on the dorsal side of the telson before its end 3 pairs of 

 sublateral spines are inserted, and the posterior pair of these spines longer than the terminal pair. 



Length of two females without marsupiuin 7 — 7.1 mm. 



Remarks. M. spiniventris agrees with Diastylofsis (?) dubia Bonnier in having third and fourth 

 thoracic segments completely fused, in general outline, etc., but it differs in having the transverse sattle- 

 shaped depression on the carapace, in the spines on the anterior part of carapace with pseudorostrum, in the 

 relative length of the joints in the antennular peduncle and the armature of its first joint, in the upper anten- 

 nular flagellum, in the extreme reduction of the exopods on third and fourth pairs of legs, in the armature of 

 first abdominal segment, in haying no lateral serration on the proximal part of telson, while its terminal 

 part has 3 pairs of dorsal spines, finally in the number of spines on the endopod of the uropods. — M. spini- 

 ventris agrees more with Diastylis longipes G. O. S. as figured and described by G. O. Sars and Bonnier, and 

 in spite of several differences I should have considered my animals as younger specimens of the last named 

 species, if both Sars and especially Bonnier had not most distinctly figured third and fourth thoracic segments 

 as well separated respectively by a suture and an articulation across the dorsal side; it may, for the rest, be 

 added that there is such differences between Sars' representation of the immature male and Bonnier's descrip- 

 tion and figures of the immature female of D.lon^ipcs, that it does not seem unthinkable that the two authors 

 have examined animals of different species. 



In the remarks on Makrocylindrus (p. 65) I have said why I refer the new form to this genus. 



Occurrence. Not taken by the "Ingolf", but by the "Thor" at a single station. 



South-West of. the Faeroes: Lat. 6i°i5' N., Long. 9°35' W., 463 — 515 fath. ; 3 immature females. 



Diastyloides G. o. Sars. 



Of the two species hitherto known at least one and probably both live within the "Ingolf" area, 

 but have not yet been found there, while a third, undescribed form has been gathered. 



60. Diastyloides scabra n. sp. 

 (PI .IV, fig. 7 a). 



Adult Female. The single specimen is somewhat mutilated with a part of the carapace broken, 

 but the species can easily be made recognizable. Carapace as to general outline, shape of pseudorostrum, and 

 serration on a little more than half of the lower margin as in D. biplicata G. O. S., but it has no vestige of 

 dorso-lateral keels or plicae, and its surface is scabrous, covered with distinct sharp granules ; almost the post- 

 erior half of the lower margin is not serrated but seen from below crenulated. Postero-lateral angles of last 

 thoracic segment produced into an acute point. The two anterior abdominal segments each with a pair of 

 sublateral denticles near the posterior margin. Abdomen slender; fifth segment long, nearly as long as second 

 and third segments together, and twice as long as the sixth segment. 



9* 



