70 Bulletin, Vanderhilt Marine Museum, Vol. II 



Genus : INACHUS Fabricius. 

 Inachnus dorsettensis (Pennant). 



Plate 18. 

 Name : Derived from the type locality. 



Type: Pennant's type specimens came from Weymouth and were 

 originally deposited in the Portland Cabinet. 



Distribution: From the Norwegian seas, the British Isles and 

 southward on the west European coast, also in the Mediterranean Sea 

 and Adriatic Sea. 



Material examined: One male infested with SaccuUna neglecta 

 (Fraisse), dredged in 325 fms., 38 miles S. E. i^ E. of Cape Sparti- 

 vento. Island of Sardinia, July 22, 1927. One specimen dredged in 

 100 fms., 91/2 miles E. by S., 1/2 S., of Cape Bon Tunis, North Africa, 

 July 19, 1927. 



Technical description : Carapace triangulate, rostrum short, bifid, 

 with a deep median groove on the upper surface ; orbital margin rim- 

 like; postorbital angle an acute, triangulate tooth. Hepatic, gastric, 

 branchial and cardiac regions well separated by deep depressions. 

 Hepatic lobe produced to a sharp tooth on the lateral margin; there 

 are one or two small, sharp spines on the pterygostomian region ; the 

 gastric lobe is much elevated with a broad, transverse row of four 

 spines across the anterior part, one pair of these being submedian, 

 the outer pair being one each on the summit of the lateral gastric 

 lobe; posterior to this the summit of the gastric lobe is produced to 

 one very acute, up-pointing spine in the median line. There is a simi- 

 lar long spine on the summit of the cardiac region and approximately 

 in line with this on either side on the summit of the branchial region 

 is a similar long spine ; behind these branchial spines placed just above 

 the posterior margin is an eminence on the intestinal region. 



The male chelipeds are very massive, twice or more than twice as 

 long as the carapace with the merus and carpus spinulose on the upper 

 and outer surfaces ; the palm is greatly swollen, relatively smooth, the 

 fingers nearly as long as the palm and decidedly incurved. 



The ambulatories are exceedingly long and slender, with long dac- 

 tyli. The first ambulatories are much longer than the chelipeds. 



The basal antennal segment has a granulose tooth at its outer distal 

 angle. 



