184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.5 



Genus LYSIOSQUILLA Dana, 1852 



The genus has been fully defined by Kemp. With regard to the soft 

 elongated papillae found on the antennal protopodite, Kemp remarks that 

 they are found perhaps in all species of the genus. He says, "These are 

 well developed in L. maculata and are three in number, one situated 

 antero-dorsally and curved backwards and inwards towards the rostrum 

 and two on the ventral surface at the base of the endopod, a long one 

 directed forwards and a much shorter one pointing backwards. In 

 L. acanthocarpus, L. rmiltifasciata, L. spinosa, and L. insignis only one 

 of these processes is found placed on the ventral surface and pointing out- 

 wards or backwards." To this list of species having just one of these proc- 

 esses ventrally placed may be added L. biminiensis Bigelow and L. digueti 

 Coutiere, which have the process long and slender, and L. latifrons 

 de Haan, in which the process is short and really papillalike. L. excava- 

 trix Brooks seems to have at least one small papillalike process below; 

 the larger of the 2 small specimens which I have had available for 

 examination is in very poor condition, while the smaller one is too young 

 apparently to have developed the papilla. L. decemspinosa Rathbun, of 

 which there are several specimens in the National Collections, is perhaps 

 a juvenile or late larval form, all of the specimens are quite small, and I 

 have not been able to discover any papillalike structures in any of them. 

 L. polydactyla von Martens has 2 papillalike processes below. 



Three species may be placed alongside L. maculata in possessing 3 

 elongated papillae more or less comparably placed: L. glahriscula (La- 

 marck), L. scabricauda (Lamarck), and L. armata Smith. 



Two other species, L. eusebia (Risso) and L. rnccullochae, described 

 below have 4 processes, 2 below, of which the anterior is the longer, and 

 2 on the inner margin of the protopodite, both inclined obliquely for- 

 ward and visible from above as well as from below. 



In Lysiosquilla the inner ramus of the 6th, 7th, and 8th thoracic 

 limbs seems always to be composed of 2 segments ; in Pseudosquilla it may 

 be composed of one or of two segments (see Pseudosquilla, p. 170). 



In Lysiosquilla the size, number, and arrangement of the marginal 

 spines or teeth and the spinules or denticles between them when these are 

 present^^ vary to such an extent that it is difficult to find a formula that 

 would clearly express the number and relationship of the various elements 



59 In Lysiosquillas of the second type of Kemp (Mem. Indian Mus., Vol. 13, 

 No. 4, p. 109, 1913). 



